This seems so simple yet I have not seen it after launching products on the Google Apps Marketplace, Chrome Web Store, iTunes App Store, Android Market, and BlackBerry App World over the past couple years.
Travel review site TripAdvisor does a nice job of allowing the property to comment back when a review is given (positive or negative) with additional details, an explanation, or just an update that an issue was resolved.
There is no such capability in these app marketplaces and it would be a really nice both for marketing efforts and, more importantly, customer support. In fact, in several cases we've commented back to a review by creating a review. This is all very clumsy and doesn't really solve the problem.
Anybody working on this or adding this capability soon? If you have an app marketplace, you should be.
Venture Vice 
So true! It’s kind of frustrating for both sides – the developer and the user.
Let’s assume there is a problem with an app. A user dicoveres this and votes/comments negative. Even if the developers fixes the problem within some hours the user will probably never come back and the negative voting won’t go away forever.
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