Not necessarily! The shop owner wants reviews for the attention it will bring to his shop. Perhaps there is no good or bad news but thinking makes it so. In other words, all publicity is good publicity!
It takes time and effort to write a review, and the more entertaining and informative it is, the more time and effort it takes. The reviewer, far from being paid for this effort, is still forking out a net amount of money regularly for the privilege of spending time and effort afterwards on reviewing.
It sounds like the shopowner might realise that the occasional poor review is not going to outweigh the number of good reviews. None of them would be "made up" - it would just be the law of averages at work. So it could work if the shopowner is mature enough to take the bad with the good. In that way all reviews from the shop would come with an official
Otherwise the shop or gets **** all reviews! Hence his request.
It is all theoretical though, as it seems that regular reviewers seem to be pretty thin on the ground - your good self being one of them oneonone.