How the Meta Ads Algorithm Works in 2026 and What It Means for Your Campaigns

What the Algorithm Decides vs. What You Decide

You decide: campaign objective, budget, base audience, creatives, placements. The algorithm decides: exactly who sees the ad, when, how often, and what each placement costs.

How the Meta Ads Auction Works

Total Value = Bid × Estimated Action Rate × User Value. A more relevant ad can win auctions against competitors with larger budgets. The creative directly impacts your cost per result.

The Learning Phase: Why It's Critical

Learning ends after 50 optimisation events per ad set per week. If you're optimising for purchases and making fewer than 50/week per ad set, learning never completes. Solution: consolidate ad sets (fewer, larger budget per set) or optimise on a more frequent upstream event.

What Resets Learning (to Avoid)

Changing budget by more than 20% at once, changing audiences, changing creatives within an active ad set, changing the optimisation objective, pausing for more than 7 days. To test a new creative, create a new ad set rather than adding it to an existing one.

Advantage+ in 2026

Advantage+ Shopping works well for eCommerce with a product catalogue. For services or B2B, manual campaigns give more predictable results. Test both with equal budget and compare ROAS or CPL after 21 days.