What's the most cost-effective way to scale prospecting campaigns using an open auction network?

The most cost-effective way is usually to scale only the highest-intent audiences in the open auction, then optimize relentlessly toward marginal CPA/ROAS instead of raw reach.

A practical approach:

1. Start with narrow, high-signal targeting

   • Use first-party data, lookalikes, site visitors, CRM lists, and in-market/contextual signals.
   • Avoid broad prospecting until you have strong conversion signals.

2. Use value-based bidding or tCPA/tROAS where possible

   • Let the auction find cheaper converters, not just cheap clicks.
   • Feed it enough conversion volume for the algorithm to learn.

3. Prioritize efficient inventory

   • Exclude low-performing placements/apps/sites.
   • Focus on placements with strong viewability, fraud controls, and historical conversion rates.

4. Build layered audiences

   • High-intent segments first, then expand incrementally.
   • Scale from seed audiences to modeled audiences before broadening to general prospecting.

5. Optimize creative before increasing spend

   • In open auction, creative often drives the biggest efficiency gains.
   • Rotate multiple variants and cut losers fast.

6. Use frequency caps and recency controls

   • Prevent waste from overexposure.
   • Tighten caps as you scale.

7. Scale budget gradually

   • Increase spend in small steps to avoid resetting learning or bidding too aggressively.
   • Watch CPA, conversion rate, and impression quality as budget rises.

8. Measure incrementality

   • Don’t just chase cheapest attributed conversions.
   • Use holdouts or geo tests to ensure the open auction spend is adding real net-new business.

If you want, I can turn this into a step-by-step scaling playbook for DSPs like DV360, The Trade Desk, or Meta-style open auction buying.