That is genius! I never even considered implementing a suggestion into the app, seems like an easy way to obtain ratings as long as it's not too intrusive. I'm definitely including it in future updates.
If someone is willing to launch your app five times, they probably find it useful, and ought to be pretty willing to rate it highly. Or at least, that's the theory right? :)
I do this, but found it _tons_ more effective to open the "reviews" section of the app itself. Lower friction, etc.
I was actually thinking of releasing some code that does this - essentially it monitor the ratings an app gets and dynamically settle on the best time to ask for a review.
Basically, to open direct to reviews, you want to construct an 'itms-apps://' url.
Then, rather than setting the "check at" interval to something fixed (which also works well), you can have the app check in the background what it should do.
So you can do things like: performSelector:withObject:afterDelay with a custom message after a custom number of starts, or a minimum number of starts after the app has been used for such-and-such a long time.
At the same time, you can monitor the reviews (frequency & stars) and vary over your stats over time. Unfortunately you can't straight A/B test at the same time, as you don't know who wrote which review, but you can A/B test if you separate them by time.
Hope that helps. Feel free to contact me directly: einar@lcrnd.com
This is a bit how Amazon works. I can't recall the last time I went back to review a purchase on my own. That always came from the review reminder e-mail Amazon sends out several days after the order arrives.