Content Writer for Whistle with multidisciplinary experience spanning over a decade.
Building a high-performing sales development team in-house has become increasingly challenging for B2B companies. The average cost to hire and train a single SDR now exceeds $75,000, with typical ramp times extending 3-6 months before seeing meaningful results.
Add in turnover rates averaging 35-40% annually, and many businesses are discovering that SDR outsourcing offers a more predictable, scalable path to consistent lead generation.
The challenge lies in selecting the right SDR outsourcing partner. Our clients tell us that evaluating potential providers typically consumes 4-6 weeks of executive time, requiring extensive research, vendor calls, and proposal reviews just to narrow down the top contenders.
Having worked with dozens of companies through their SDR outsourcing evaluation process, we’ve compiled this comprehensive guide to save you time and ensure you make the best decision for your business. Each company listed has been thoroughly vetted based on client results, industry reputation, and service quality.
Interested in learning more about building a predictable sales pipeline? We offer strategy meetings to help B2B companies optimize their lead generation approach.
# | Company | Specialties | Pricing Range |
1 | Whistle | Multi-channel outreach, enterprise focus, guaranteed meetings | $5,000-$12,000/month |
2 | SalesRoads | Full-scale outbound, telemarketing focus | $5,400-$9,500/month |
3 | CIENCE | Human + AI approach, global reach | $3,000-$8,000/month |
4 | Belkins | Multi-channel campaigns, tech specialization | $5,000-$14,800/month |
5 | MarketStar | Enterprise solutions, industry expertise | Custom pricing |
6 | OutboundSquad | LinkedIn focus, personalized outreach | $4,000-$10,000/month |
7 | LeadGenius | Data + SDR services, compliance focus | $6,000-$12,000/month |
8 | SalesLoft (Managed) | Platform + managed services | $8,000+/month |
9 | Operatix | International markets, complex sales cycles | Custom pricing |
10 | Pearl Lemon | Cost-effective, growing companies | $2,500-$6,000/month |
Website: www.whistle.ltd
Whistle stands out in the SDR outsourcing space by focusing exclusively on enterprise and mid-market B2B companies with complex sales cycles. Founded in 2019, they’ve built a reputation for delivering consistent, high-quality appointments through their data-driven methodology and rigorous quality standards.
Unlike many providers who compete on volume, Whistle guarantees specific meeting outcomes and maintains one of the industry’s highest show rates at 87%. Their client retention rate of 94% reflects their commitment to long-term partnership rather than short-term lead generation.
Whistle’s process starts with building a strong strategic foundation through deep customer analysis, competitive research, and Ideal Customer Profile (ICP) development. From there, they design multi-channel campaigns across LinkedIn, email, and phone that build familiarity and trust through carefully sequenced touchpoints.
Dedicated SDR teams execute and optimize these campaigns for consistency and specialization, while seamless warm handoffs ensure sales teams receive fully qualified meetings with complete context, pain points, and next steps for a smooth transition.
Whistle’s investment typically ranges from $5,000-$10,000 per month, with most clients averaging $8,500 monthly for comprehensive SDR services. Their performance-based pricing model aligns their success with yours, ensuring you only pay for results that drive real business growth.”
⭐⭐⭐⭐⭐ (4.9/5 stars)
Based on client reviews, retention rates, and performance metrics
Website: salesroads.com
SalesRoads has been a stalwart in the B2B lead generation space for over 13 years, building its reputation on high-volume telemarketing campaigns and comprehensive outbound strategies. They specialize in creating end-to-end sales development programs that combine phone-based prospecting with email and social outreach.
Their strength lies in rapid deployment and scalable campaigns, making them ideal for companies needing immediate pipeline acceleration. With over 200 SDRs and a proven playbook approach, SalesRoads can launch campaigns within 2-3 weeks of engagement.
SalesRoads follows a systematic approach, starting with a comprehensive business analysis and market research phase. They create detailed buyer personas and develop multi-touch campaigns spanning 6-8 weeks per prospect cycle.
Their process emphasizes phone-first outreach, with SDRs making 80-120 calls daily, supported by coordinated email sequences and LinkedIn touches. Each campaign includes A/B testing of messaging, timing, and approach to optimize performance continuously.
$5,400-$9,500/month depending on campaign scope and dedicated resource allocation.
Based on G2 and client reviews on their own website
Website: cience.com
CIENCE combines human intelligence with artificial intelligence to deliver scalable lead generation solutions. Founded in 2015, they’ve developed a unique methodology that uses machine learning to optimize outreach while maintaining the personal touch of human SDRs.
Their platform approach allows for sophisticated campaign management and real-time optimization, making them suitable for companies wanting data-driven results with transparent reporting.
CIENCE’s approach centers on their proprietary GO Platform, which integrates prospect research, outreach execution, and performance tracking. Their SDRs handle 40-60 personalized touches per day, with AI assistance in research and initial targeting.
They emphasize multi-channel sequences with 8-12 touchpoints over 6 weeks, including email, LinkedIn, phone calls, and even direct mail for high-value prospects.
$3,000-$8,000/month based on volume and service level requirements.
Based on sites like G2 and Clutch
Website: belkins.io
Belkins focuses specifically on B2B technology companies, bringing deep expertise in SaaS, cybersecurity, fintech, and IT services. Since 2017, they’ve built a reputation for sophisticated, multi-channel campaigns that resonate with technical buyers.
Their approach emphasizes education and value-first messaging, making them particularly effective for complex technology sales where prospects need significant education before engaging.
Belkins starts with market fit validation, testing hypotheses about target audiences and messaging before full campaign launch. They design integrated campaigns across email, LinkedIn, and phone that focus on providing value and building relationships rather than immediate sales.
Their SDRs undergo extensive training in technology topics and consultative selling approaches, enabling more meaningful conversations with technical decision-makers.
$5,000-$14,800/month depending on campaign complexity and target market requirements.
Based on sites like Gartner and Clutch
Website: marketstar.com
MarketStar is an enterprise-focused sales acceleration company with over 35 years of experience. They provide comprehensive sales outsourcing solutions extending beyond SDR services, including inside sales, channel partner management, and customer success.
Their strength lies in handling large, complex programs for Fortune 500 companies, with deep expertise in technology, healthcare, financial services, and telecommunications.
MarketStar’s approach is highly consultative, starting with extensive discovery and strategy development. They create custom sales playbooks and provide dedicated program management for each client.
Their SDRs are industry specialists with extensive training in specific verticals, enabling sophisticated conversations with executive-level prospects.
Custom pricing based on program scope, typically starting at $15,000+/month for enterprise engagements.
Based on Clutch reviews
Website: outboundsquad.com
OutboundSquad specializes in LinkedIn-based lead generation with an emphasis on highly personalized, relationship-building approaches. They’ve carved out a niche serving B2B service companies and consultancies that sell to business executives.
Their methodology focuses on quality over quantity, with SDRs handling smaller prospect volumes but investing significant time in research and personalization for each interaction.
OutboundSquad’s approach centers on deep prospect research and ultra-personalized messaging. Each SDR handles 20-30 prospects per day, spending 5-10 minutes researching each person before crafting custom LinkedIn connection requests and follow-up sequences.
They emphasize building genuine relationships and providing value before making any sales-related requests, resulting in higher response rates but longer sales cycles.
$4,000-$10,000/month based on volume requirements and personalization level.
Based on Clutch reviews
Website: leadgenius.com
LeadGenius combines premium data services with SDR outsourcing, making them unique in providing both high-quality prospect lists and the outreach execution. They specialize in regulated industries where compliance and data accuracy are critical.
Their strength lies in serving financial services, healthcare, and legal industries where data quality and regulatory compliance are paramount concerns.
LeadGenius starts with comprehensive data validation and list building using both automated and human verification processes. Their SDRs receive extensive compliance training and work within strict guidelines for regulated industries.
They emphasize consent-based outreach and maintain detailed records for audit purposes, making them ideal for companies with strict compliance requirements.
$6,000-$12,000/month, including data licensing and compliance infrastructure.
Based on G2 reviews
Website: salesloft.com
SalesLoft offers managed SDR services as an extension of their sales engagement platform, providing clients with both the technology and the human resources to execute campaigns. This hybrid model appeals to companies already using SalesLoft or those wanting platform + service integration.
Their managed services team consists of SalesLoft-certified SDRs with deep expertise in the platform’s capabilities and best practices.
SalesLoft’s managed services leverage their platform’s advanced capabilities, including AI-powered personalization, conversation intelligence, and sophisticated cadence management. SDRs execute campaigns while continuously optimizing based on platform analytics.
The approach emphasizes data-driven optimization with real-time adjustments based on engagement metrics and conversation outcomes.
$8,000+/month plus platform licensing fees.
Based on G2 reviews
Website: operatix.com
Operatix specializes in international B2B lead generation, with particular expertise in European, APAC, and emerging markets. They excel at navigating complex, multi-stakeholder sales cycles in enterprise technology and professional services.
Their global team and cultural expertise make them ideal for companies expanding internationally or selling into diverse, multinational accounts.
Operatix employs a consultative, relationship-focused approach that accommodates longer sales cycles and complex decision-making processes. Their SDRs are trained in cultural nuances and business practices across different regions.
They emphasize account-based approaches for enterprise prospects, with dedicated resources for major opportunities and sophisticated nurturing campaigns.
Custom pricing based on geographic scope and complexity, typically $10,000+/month for international programs.
Based on Clutch and G2 reviews
Website: salespipe.com
Salespipe specializes in building predictable sales pipelines through systematic SDR processes and data-driven approaches. Founded with a focus on measurable results, they serve mid-market B2B companies looking for consistent lead generation with clear ROI metrics.
Their methodology emphasizes pipeline velocity and conversion optimization, making them ideal for companies that need to demonstrate clear attribution from SDR activities to closed revenue.
Salespipe begins each engagement with comprehensive pipeline analysis, identifying bottlenecks and optimization opportunities in the client’s existing sales process. They then design SDR campaigns specifically targeted at filling pipeline gaps and accelerating deal velocity.
Their SDRs are trained in consultative qualification techniques, ensuring that meetings booked advance through the sales pipeline rather than stalling at initial conversations. They maintain detailed tracking of pipeline progression from initial contact through closed deals.
$4,000-$9,000/month based on pipeline targets and dedicated resource allocation.
Choosing the right SDR outsourcing partner can transform your sales pipeline from unpredictable to systematic, from reactive to proactive. The companies listed above represent the best options available, each with distinct strengths suited to different business needs.
Remember that successful SDR outsourcing requires more than just vendor selection – it demands clear communication, realistic expectations, and ongoing optimization. The most successful partnerships treat outsourced SDRs as an extension of the internal team, not as a separate service provider.
Whether you choose Whistle for enterprise-grade results or another provider better suited to your specific needs, the key is taking action. Every month without a systematic lead generation process represents missed opportunities and slower growth.
Ready to explore your options? Contact our team for a free strategy consultation where we’ll help you evaluate your specific needs and recommend the best path forward for your business.
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