What do the ad connectors actually pull?

They pull your daily spend, per ad account and per campaign, and nothing else. No revenue the platform claims for its ads, no conversion counts and no audience data. That is on purpose. Each platform claims some of the same sales, so their claims cannot be added up.

The first sync of an account goes back as far as the platform allows. That is about three years on Meta, three on TikTok and ten on Google Ads. After that, every sync reads at least the last 30 days again, because platforms keep correcting their numbers. It also reads every day since the account last synced. So an account that was paused for a while comes back without a gap.

Spend counts on the day the platform recorded it, in Marketing Costs, the ad spend line of your P&L. Open that line to see one row per platform. Spend from an account that bills in another currency than your store is converted into your store's currency. nouz uses the reference rate of the European Central Bank (ECB) from before the day of the spend, the same rule as for orders. The P&L says when spend in a range was converted. If no rate can be found yet, that spend counts one to one until a later sync converts it, and the P&L says that too. nouz also tells you when you pick such an account, because often the store currency is set wrong.

Campaigns you archived or deleted keep their spend. nouz asks Meta and TikTok for campaigns of every status, and Google Ads reports deleted campaigns anyway. Two kinds of TikTok spend are not included: posts boosted with Promote in the TikTok app, and GMV Max campaigns for TikTok Shop. Add those on the Overhead page, under Add cost, then Marketing spend.

So Marketing Costs shows what really left your account each day. Your ad numbers, such as MER, compare your own revenue with that spend, not with a platform's claim. MER is your net revenue divided by your ad spend.