Right now, they're pretty meaningless, because often, the majority those that take time to review them are counterfeit. 90% of the people that use an app never take time to review it. So I never know what most people think.

> I shudder when I think of the ways you could game a system like this.

As it stands, I can't think of how there would be more gameability to a system like this vs. ratings. Ratings are so easy to game, anybody can do it, and it doesn't cost them anything.

To game something like this, I would have to "game" it over long periods of time. Not to mention, I would have to purchase a separate device, or sacrifice my own time with my device.

It's a much more painful process to game something like this.

> If longer time-in-app is a positive signal, I could easily make my app slower.

If you make your app slower, you are sacrificing user experience, which will eventually hurt your usage. How could you game your own app without it hurting the usability of it?