Due diligence

Diligence is where a good price is made or a bad deal is caught. At minimum it means connecting the revenue to a source (a payment processor, an ad dashboard, analytics) rather than trusting a screenshot, and understanding how exposed the traffic and revenue are to a single channel.

It also means pricing the owner out: what does the seller personally do that a buyer will have to replace, and what breaks when they leave? The cleaner the answer, the safer the multiple.