Written by: Michał Sobieraj, Operations Manager, Digital Colliers
The Commission's preliminary finding that Facebook and Instagram breach the DSA on addictive design is the sort of ruling that sits quietly in a legal update email for a week, then rewrites your media plan. If Meta is forced to change how the feed ranks and serves content, the mechanics your paid social forecast is built on stop being reliable. Not in a catastrophic way. In a slow, margin-eroding way that shows up in Q4 when you can least afford it.
Here is how I'd think about modelling it, and what the operators who move first are actually doing.
What actually changes if the feed gets re-shaped
The DSA remedies on the table are not about ad inventory directly. They target session length, autoplay, infinite scroll, recommender opacity. But every one of those knobs feeds impression supply. Less time in feed means fewer ad slots served. Fewer ad slots at flat demand means CPM pressure. Meta ad CPMs for DTC advertisers already rose year over year through 2024 and 2025, and customer acquisition cost across DTC has climbed roughly 40% since 2023. You're not modelling from a comfortable baseline. You're modelling from a base that's already stretched.
Three scenarios worth putting numbers against:
- Mild: reduced session time, 5-10% drop in impression supply, CPMs up mid-single-digits, retargeting windows shorter because return visits per user fall.
- Moderate: algorithmic reranking to reduce engagement optimisation, retargeting reach down 15-25%, prospecting audiences less predictive, ROAS on cold traffic drops before you notice it in weekly reports.
- Severe: structural changes to recommender defaults, opt-in required for engagement-optimised feed, lookalike quality degrades, and your existing creative testing cadence stops producing winners at the rate it used to.
None of these are certain. But your FY paid social forecast almost certainly assumes none of them happen. That's the exposure.
Why single-channel forecasts break in this environment
UK eCommerce grew about 3% in 2024 versus 2023. Single-digit growth is the baseline now, which means you cannot absorb a 10-15% efficiency hit on your largest paid channel by growing your way out. And roughly 30% of SKUs at a typical multi-channel brand already lose money per order once returns and ad spend are counted. A CPM shock pushes more SKUs into that bucket without anyone at the weekly trading meeting noticing until the quarter closes.
The brands I see handling this well are not the ones with the biggest budgets. They're the ones who can move spend between channels in days, not months, and still trust their attribution. That capability is not a media agency deliverable. It's a data problem.
The left-behind pattern
The operators who'll struggle share a shape. Paid social is run out of one system, email and SMS out of another, Google out of a third, and the customer database is a Shopify export that someone reconciles on a Monday. When Meta efficiency drops, they can't credibly shift 20% of Meta budget into email and SMS because they don't know which customers are already saturated on those channels. They can't push into Google non-brand because their audience exclusions live in Meta and nowhere else. So they keep spending on Meta at worse economics, because it's the only channel they can actually operate at pace.
The fast movers look different:
- One customer table that every channel writes to and reads from.
- Suppression, frequency and value segments computed centrally, not per platform.
- Attribution that survives a channel mix change, usually incrementality-tested rather than last-click.
- Creative and offer testing decoupled from any single ad platform's UI.
None of that is glamorous. It's plumbing. But it's the plumbing that lets you respond to a regulatory shift in weeks instead of quarters.
What to do in the next 60 days
You don't need to rebuild your stack before Q4. You need to know where you'd move money if you had to, and whether your data can support that move. A few concrete checks worth running:
- Model the moderate scenario against your current Q4 plan. What's the profit hit if Meta CPMs move up 15% and retargeting reach drops 20%?
- Audit whether your email and SMS platforms have a live view of paid social exposure per customer. If not, that's the first gap to close.
- Pressure-test your Google non-brand headroom. Most brands have more than they think, but only if audience data is portable.
- Decide now which SKUs you'd pull from paid social first if unit economics slip. Don't decide that in November.
The DSA ruling might get watered down. Meta might appeal for years. But your forecast shouldn't need the ruling to disappear in order to hold. The teams treating this as a data readiness question, not a media question, are the ones who'll still hit their number.