What Does an SDR Do? Functions, Skills, and KPIs Explained

If you're scaling an outbound sales engine, the Sales Development Representative (SDR) is the role that makes or breaks your pipeline. So what does an SDR do, exactly? And more importantly, how do you hire, manage, and measure one effectively?

This guide breaks down the core function of the SDR role, the daily activities that fill their calendar, the skills that separate average performers from top ones, and the KPIs you should actually track. Whether you're a founder building your first outbound team, a Sales Director expanding headcount, or a professional considering the SDR career path, this is the definitive resource.

The Core Function: What Does an SDR Do in a Sales Organization?

An SDR's primary job is top-of-funnel pipeline generation. They don't close deals. They open doors.

In a typical B2B sales structure, the SDR sits between marketing and the account executive (AE). Their responsibility is to identify, contact, and qualify potential buyers—then hand them off to the AE for the close.

Here's the simplest way to think about it:

• Marketing generates awareness and inbound interest.
• The SDR converts that interest into qualified conversations (and creates new interest through outbound).
• The AE runs demos, handles objections, and closes revenue.

Without SDRs, your AEs spend half their time prospecting instead of selling. With SDRs, your closers focus on what they do best—closing—while a dedicated team keeps the top of the funnel full.

This division of labor is why the sales development representative job has become one of the most common entry points in B2B SaaS. It's also why companies that invest in this role consistently outperform those that expect AEs to do everything. [INTERNAL_LINK: benefits of SDR staff augmentation]

Daily Activities: What an SDR Actually Does, Hour by Hour

SDR work is repetitive by design. The magic is in the consistency, not in one-off heroics. A high-performing SDR's typical day looks something like this:

Morning: Research and Outbound Sequences

• Account and contact research — Identifying target accounts that fit the Ideal Customer Profile (ICP) and finding the right decision-makers within those accounts.
• Personalized email outreach — Writing or customizing outbound emails for cold and warm prospects. The best SDRs spend time personalizing the first line, not blasting templates.
• LinkedIn prospecting — Sending connection requests, engaging with prospects' content, and sending direct messages as part of a multichannel sequence.

Midday: Calls and Follow-Ups

• Cold calling — Yes, it still works. SDRs typically make 40–60 dials per day, depending on the market and tool stack.
• Follow-up calls — Re-engaging prospects who opened an email, clicked a link, or replied with a soft objection.
• CRM hygiene — Logging activities, updating contact statuses, and moving prospects through pipeline stages in the CRM.

Afternoon: Qualification and Handoff

• Discovery conversations — When a prospect shows interest, the SDR runs a brief qualification call to confirm fit (budget, authority, need, timeline).
• Meeting booking — Scheduling qualified prospects with the AE and providing context notes so the AE walks in prepared.
• Sequence optimization — Reviewing what's working—open rates, reply rates, call connect rates—and adjusting messaging or targeting accordingly.

The average SDR sends 50–80 emails and makes 40–60 calls per day. That volume is necessary because response rates in cold outbound typically range from 1% to 5%, depending on the industry and quality of the list. [INTERNAL_LINK: how to build an effective outbound prospecting strategy]

SDR Functions: Inbound vs. Outbound

Not all SDR roles are identical. The two main flavors are inbound SDRs and outbound SDRs, and the SDR functions differ significantly between them.

Inbound SDRs

Inbound SDRs respond to leads generated by marketing—demo requests, content downloads, free trial sign-ups, webinar attendees. Their job is speed-to-lead: contacting the prospect quickly, qualifying the opportunity, and booking a meeting with the AE.

Key traits of inbound SDR work:

• Faster response time matters more than creative outreach
• Lead volume is higher, but quality varies
• Qualification skills are paramount

Outbound SDRs

Outbound SDRs are hunters. They start from scratch—building lists, crafting cold outreach, and engaging prospects who haven't raised their hand. This is harder, takes longer, and requires more resilience.

Key traits of outbound SDR work:

• Prospecting and research skills are critical
• Messaging creativity directly impacts results
• Rejection rate is high; mental toughness is non-negotiable

Many companies need both. If you're early-stage with limited marketing, outbound SDRs are your lifeline. If you've got strong inbound demand, inbound SDRs ensure none of it goes to waste. [INTERNAL_LINK: inbound vs outbound lead generation comparison]

SDR Skills: What Separates High Performers from the Rest

Hiring for the SDR role is deceptively hard. The skills that make a great SDR aren't always the ones on a resume. Here are the SDR skills that actually predict success:

1. Written Communication

Most SDR outreach starts with an email or LinkedIn message. High performers write concise, relevant messages that earn a reply. They don't rely on templates alone—they personalize based on research.

2. Active Listening

On calls, the best SDRs listen more than they talk. They ask smart qualifying questions and pick up on buying signals (or disqualifying signals) that average reps miss.

3. Resilience and Coachability

SDRs hear "no" dozens of times a day. The ones who last and perform are the ones who don't take rejection personally—and who actively seek feedback to improve. According to Bridge Group's 2023 SDR Metrics Report, the average SDR tenure is just 1.4 years, partly because many reps burn out before they build real skill.

4. Research and Pattern Recognition

Strong SDRs spot signals in a prospect's LinkedIn profile, recent company news, or tech stack that make outreach relevant. This is a skill that gets sharper with practice and good data tools.

5. Time Management

With 50+ emails, 40+ calls, CRM updates, and research all in one day, the ability to prioritize ruthlessly is essential. Top SDRs build daily routines and stick to them.

6. Basic Technical Fluency

SDRs work with CRMs (Salesforce, HubSpot), sales engagement platforms (Outreach, Salesloft, Apollo), and LinkedIn Sales Navigator daily. They don't need to be engineers, but they need to be comfortable with tools and data.

SDR KPIs: What to Measure (and What to Ignore)

Measuring SDR performance is where a lot of sales leaders get it wrong. They either track vanity metrics or set unrealistic targets. Here are the SDR KPIs that actually matter, along with realistic benchmarks.

KPIWhat It MeasuresBenchmark RangeMeetings Booked per MonthVolume of qualified meetings set with AEs12–20 per month (outbound); 15–25 (inbound)Qualified Opportunities CreatedMeetings that convert to real pipeline60%–75% of meetings bookedPipeline Value GeneratedTotal dollar value of pipeline attributed to SDR activityVaries by ACV; target 3–5x SDR costActivities per DayEmails sent, calls made, LinkedIn touches80–120 total touchpoints/dayReply RatePercentage of outreach that gets a response5%–15% (email); 10%–25% (LinkedIn)Call Connect RatePercentage of dials that reach a live prospect3%–7%Speed-to-Lead (inbound)Time between lead submission and SDR contactUnder 5 minutes is ideal

A Note on Realistic Expectations

These numbers assume a well-defined ICP, clean data, a tested messaging framework, and proper tooling. If you drop a new SDR into a role with no playbook and a purchased list of questionable quality, expect results below these ranges for the first 2–3 months at minimum.

Ramp time matters. According to Bridge Group data, the average SDR takes 3.2 months to fully ramp. Plan for it. [INTERNAL_LINK: how to reduce SDR ramp time]

When to Build vs. When to Outsource SDR Functions

Here's the practical question most leaders eventually face: should you build an in-house SDR team, or partner with a specialized agency?

Build in-house when:

• You have the management bandwidth to recruit, train, and coach reps
• Your sales cycle requires deep product knowledge that takes months to develop
• You're ready to invest in tooling, data subscriptions, and ongoing enablement

Outsource or augment when:

• You need pipeline now and can't wait 3–6 months to hire and ramp
• You want to test outbound in a new market or vertical before committing to full-time headcount
• You need experienced SDRs with proven playbooks, not trainees
• Your internal team is at capacity and you need to scale without the overhead

SDR staff augmentation gives you trained reps, proven processes, and faster time-to-pipeline. It doesn't replace in-house teams—it complements them or buys you time while you build.

Conclusion: The SDR Role Is the Engine of B2B Pipeline

So what does an SDR do? They generate the qualified conversations that feed your entire revenue engine. Without them, your AEs prospect inefficiently, your pipeline dries up, and growth stalls.

The sales development representative job demands a specific mix of skills—written communication, resilience, research ability, and tool fluency. And managing SDRs requires tracking the right KPIs with realistic benchmarks, not just counting dials.

If you're looking to scale your outbound pipeline without the time and risk of building from scratch, Siete provides experienced SDRs and proven lead generation frameworks designed for B2B companies ready to grow.

Book a call with our team and let's talk about what pipeline growth looks like for your business.