Hello, thanks but I don't fully understand your reply, what vouch? please explain again on other words, and sorry for the delay.
A vouch is a free copy that you give to a high ranking member. The member then tests out the product/song/album/whatever you're selling and then leaves a review reporting the quality of whatever was sold to them. Basically, with good vouches your product can end up being sold more and you becoming a trusted seller. The opposite happens with bad reviews.