If advertising drives sales then you will see a decline really quickly if you cut spending. You’ll likely see this decline within hours. In order to restore sales the first thing you’ll do is restore spending.

You’re not going to wait to collect a bunch of data in order to be able to roll it up into meaningful research for a blog post because those lost sales are real money that you’re losing.

The thing is, it’s in AirBNBs interest to discredit advertising because they have a huge organic advantage over their competition. If I want to rent a holiday place somewhere, I’m going to search AirBNB first. Only if it doesn’t work out will I try a broader search, and be exposed to AirBNBs competitors.

Competitors won’t want to publicise the fact that ad spending is important because it gives them an advantage over those who believe AirBNBs argument.