You're right, I obviously can't prove it, but here's one sample point. I subscribe to an RSS feed of iOS apps that have recently become free. Many of these are unsuccessful games that are trying to attract some attention. Some of them are interesting — maybe even good — but I don't think I've ever seen any as beautiful and polished as, say, Monument Valley or Dextris (just to name two of the current iOS darlings). On the other hand, occasionally I spot a game in the App Store new releases that looks really cool. If it captures my attention, chances are it'll soon get mentioned on TouchArcade or on Twitter.