You might want to make sure that you're first on queue if you sign up your site and do a bunch of reviews.

I just did three reviews and it should've been possible to make sure I got one in return by now, but that didn't seem to happen yet (or is it because my site is HTTPS only?)

I can second the comment about star ratings as well; the default of 1 star especially was not in line with my intent for at least one of my reviews.