Social Proof

Myth:A big enough A/B test or attribution platform can pin down each campaign's ROI.

Evidence:Across 25 large field experiments with major U.S. retailers and brokerages, the median confidence interval on ad ROI was over 100 percentage points wide; individual-level sales are so volatile (coefficient of variation ~10) that an informative test often needs 10M+ person-weeks.

Myth:Long checkouts are fine if the product is good.

Evidence:Average large-site checkouts ask for far more fields than necessary; trimming to the minimum viable set is one of the highest-yield conversion changes available.

Myth:Display ad ROI shows up in online conversions.

Evidence:A randomized experiment with 1.6 million Yahoo! users found display ads profitably lifted a major retailer's purchases by 5% - but 93% of the increase happened in brick-and-mortar stores, and 78% came from customers who never clicked the ads.

Myth:Forcing account creation builds your CRM.

Evidence:Mandatory account creation is a top-cited abandonment driver; guest checkout with a post-purchase account offer captures both revenue and the record.

Myth:Retail media ROAS proves the channel works.

Evidence:Most retail-media ROAS counts sales that would have happened anyway; even incremental ROAS is so methodology-sensitive that Ovative, Albertsons Media Collective and Kellogg faculty built a framework just to standardize it.