It's the latest thing in advertising and instantly takes the crown for the most irritating. That's a crowded field, what with YouTube ads that play one fifth of a second of the video you want before running a commercial. Or all the popups over YouTube. It's mostly YouTube that's irritating, isn't it? But now we have ads where you read some website on your iPhone or iPad and before you take in a word, you are bounced out of Safari and into the App Store to buy some particular app.
Invariably that seems to be a game one. Usually you can see an ad for that same game on the site but sometimes there doesn't appear to be any connection between the site advertisers and the App Store game.
What there isn't – necessarily – is collusion with the website. Like you, I presumed that this was the latest type of ad that was being sold by websites to advertisers. But one major site told me that it was done without their knowledge or permission and definitely without any extra money being paid to them. He described it as the advertisers playing silly buggers and it was stopped.
It's a bit of an old-fashioned approach, but it can work.