Jeremy Provost, on the blog for Think Tap Work, his mobile app development company:

iOS App Store search is no longer about relevance. It’s about ad inventory. With Apple’s introduction of a second search ad, for any query where we weren’t #1, we’ve effectively moved down one position. [...] If you’re counting at home, roughly 70% of the interface is covered in ads. A casino ad, to boot.

That was a month ago. Two weeks later, he posted a follow-up, showing the effect on Think Tap Work’s apps in the App Store:

I wanted to share some updated numbers from our own apps. To isolate the impact, these numbers only include App Store Search impressions from iOS devices, comparing Mar 26–Apr 8 to the prior two weeks. In other words: how much visibility we’ve lost in search.

• Morpho Converter: 26% decrease
• Pop Out Timer: 23% decrease
• Attendant for Zoom: 30% decrease
• Participant: 3% increase. As previously mentioned, we advertise Participant using Search Ads. It’s not surprising that it might be getting a bump from this change.

The screenshot in his follow-up shows another casino ad, this time in a search for “Roblox”. Kinda gross.

Here’s Wikipedia on the “Zero-One-Infinity Rule”:

The zero-one-infinity (ZOI) rule is a rule of thumb in software design proposed by early computing pioneer Willem van der Poel. It argues that arbitrary limits on the number of instances of a particular type of data or structure should not be allowed. Instead, an entity should either be forbidden entirely, only one should be allowed, or any number of them should be allowed.

In Apple Notes, you can only have one main window open. In Apple Mail, however, you can open as many Viewer Windows as you want. Both are compliant with the Zero-One-Infinity rule. An app that allowed you to open multiple viewer windows — but no more than some arbitrary limit — would not be. ZOI is a very good rule of thumb.

I feel like a variation of Zero-One-Infinity is a good rule of thumb for ads, too. From the perspective of users — and probably developers — zero was the best number of ads for Apple to show in App Store search results. One was worse but acceptable. But now that they’re showing more than one, they’re on their way to infinity. They’ve started down the slippery slope. Remember when Google only showed one ad in search results?

Anyway, who’s looking forward to ads in Apple Maps this summer?