have you checked whether that CPM drop is actually a warning sign of traffic quality going south rather than an improvement?
A 50% CPM fall combined with sales tanking to almost nothing usually points to trouble, not opportunity. most people cheer lower CPMs, but when revenue collapses at the same time, it often means Meta has started pushing cheaper inventory or lower-intent audiences instead of real buyers. If your products had been doing $20-25k consistently for a few months and then performance shifted almost overnight around that date, I'd be looking at traffic quality, attribution, checkout flow, payment processing, and conversion behaviour throughout the funnel rather than blaming product-market fit. first thing I'd compare is add-to-cart rate, checkout starts, landing page engagement, and conversion rate before and after May 19.
had a similar case with an ecommerce brand spending roughly $700/day where CPM suddenly fell from about $42 to $21 in a few days. initially the team thought they'd found cheaper traffic, but purchases dropped from around 28 a day to just 3-4. CTR actually improved, CPC dropped nearly 40%, yet add-to-cart rate fell from about 9% to under 2% and conversion rate went from 3.4% to 0.6%. after digging through the account, it became clear Meta had shifted delivery into much weaker audience pockets. tightening creative messaging, rebuilding signal quality, and keeping budgets stable instead of constantly relaunching campaigns brought CPA back from roughly $96 to $38 over the next few weeks, and daily purchases recovered.
So compared to before May 19, are your add-to-cart and initiate checkout numbers also down badly, or are people still reaching checkout and just not completing?
