Every SDR model, ranked by someone who's been all of them

I've been on basically every side of this decision.

I was an in-house SDR.

I managed an in-house team.

I've seen agency and SDR-as-a-service pitches from the buyer's side.

Now I build the AI systems that replace all three.

So let's actually break this down honestly.

In-House SDR Team

Pros: Deep product knowledge, full control over process, direct alignment with sales leadership.

Cons: High fully loaded cost per rep (often $90K-$120K+ year one), 60-90 day ramp time, high turnover, constant management overhead, inconsistent output across reps.

This is the model I lived inside of for years. It works, but it's expensive and fragile.

Your pipeline is only as strong as your current team's morale and tenure.

SDR Agency on Retainer

Pros: Faster to start than hiring, no direct management burden, flexible contract terms.

Cons: Usually $6K-$10K/month, reps split across multiple client accounts so they're not fully dedicated to you, shallow product knowledge, you own nothing when the contract ends.

You're renting attention month to month with no asset left behind.

I get why this looks appealing on paper.

It's the "no long term commitment" option.

But over 12 months, you'll often spend more than an in-house hire and end up with less to show for it once you stop paying.

AI Outbound System

Pros: One-time setup cost, no ongoing salary or retainer, no ramp time, consistent output every day, fully owned by you, scales without adding headcount, you keep the system even if you stop actively using it.

Cons: Upfront investment, long-term payoff. Like any owned asset, there's a one-time build cost before it starts working for you.

After that, it's yours to run indefinitely at a fraction of the cost of a hire.

My Honest Take

If your outbound motion involves a repeatable process of targeting, researching, and starting conversations (which, let's be honest, covers most B2B outbound), the AI system wins on cost, consistency, and ownership over any 12 month period.

In-house still has a place for complex, high-touch, strategic accounts.

Agency retainers are, in my opinion, the weakest option of the three.

You get the downsides of both other models (cost and inconsistency) without the upside of ownership or deep product knowledge.