How paid ads actually work

Every major ad platform runs an auction. Advertisers bid; the platform picks winners based on bid + expected outcome + ad quality. Understanding this mechanism changes how you think about targeting, bidding, and creative.

The auction in 60 seconds

When a user triggers an ad slot, the platform looks at every advertiser who's eligible to show. For each, it computes:

Expected revenue to platform = bid × expected conversion rate × ad quality

Highest expected revenue wins. The platform optimizes its own revenue, not yours.

What this means for you

• Creative quality matters more than bid. A cheap ad with 3x the CTR beats an expensive ad with 1x CTR.
• The algorithm gets smarter with data. Early campaigns perform worse because the platform has no signal. Feed it conversions quickly.
• Targeting narrows the pool. Tight targeting raises costs per impression but should improve conversion rate. Broad targeting is cheaper per impression but conversion depends on creative.
• Budget pacing matters. Sudden budget increases spook the algorithm. Scale gradually.

The modern shift: creative over targeting

Post-iOS 14 and signal loss, targeting is less precise. Platforms have shifted to creative-first: the creative itself does the targeting by resonating with the right audience. Broad targeting + great creative often beats narrow targeting + mediocre creative.

What to do with this

• Invest in creative quality over bid increases, a 3x CTR bump beats a 2x bid bump every time at the auction level
• Feed the algorithm conversions fast in new campaigns, early undertrained algorithms produce inflated CACs that scare operators off working channels
• Don't jump budgets 10x overnight, scale 20-30% every 2-3 days to keep the algorithm stable
• For most platforms in 2026, default to broad targeting with great creative, the creative does the targeting now that signals are thin
• Measure the platform as a system (bid + quality + relevance), not just bid alone, understanding the auction changes how you spend