Question

After launching an ad campaign on the first day, and sometimes on the second day, I get excellent cost-per-sale. But on the third day the cost increases from 100% to 200%. All campaign data remains the same such as click-through rate (CTR), cost-per-click (CPC), cost-per-thousand impressions (CPM), etc., but the cost-per-sale increases.

Is anyone else experiencing the same problem? Do you have any suggested solutions, please?

I'm thinking maybe the frequency is low: (1.2)

Answer 1

Yes, a lot of advertisers see this pattern, a great initial cost per sale that jumps on day 2 or 3.

Here’s why it happens and what to check:

• Algorithm Front-Loading: On day 1, Meta shows your ads to the most likely buyers (“easy wins”). Once those users convert, the system has to reach less qualified people to keep delivery going.

• Learning Phase Decay: Even if your learning phase is complete, early delivery benefits fade as the campaign settles into broader targeting.

• Conversion Delay: Some of your early purchases are delayed reporting from clicks that happened in the first hours, making day 1 look cheaper.

• Audience Overlap or Small Size: If your audience is narrow, the best prospects are exhausted quickly. Even with low frequency (1.2), you’re often still burning through the most engaged users in the first 24–48 hours.

Suggested solutions

• Increase audience size or refresh creatives to give the algorithm more room.

• Segment cold and warm audiences instead of mixing them.

• Let campaigns run longer before making judgments—early performance is often artificially low cost.

• Watch 7-day trends, not just daily results.

Bottom line
This is normal. Day 1 is always the best cost, because the algorithm front-loads top prospects. As long as your CTR and CPM hold steady and you have fresh audiences, the increase in cost per sale doesn’t mean your campaign is broken—it just means the “easy buyers” converted first.