I think the fourth reason that has been discussed here and in Jeff's post also sounds plausible:
- somebody wants to push his app with fake reviews, however that would be easy to detect / trace back. Thus that person buys additional positive fake reviews for other apps (that are not in competition with his apps). This makes it really hard to tell which of the apps "purchased" the fake reviews.
- somebody wants to push his app with fake reviews, however that would be easy to detect / trace back. Thus that person buys additional positive fake reviews for other apps (that are not in competition with his apps). This makes it really hard to tell which of the apps "purchased" the fake reviews.