There seems to be a glut of people posting up ad copy from emails from magic shops... they add zero to the post/ad copy, and often admit that they don't have it, and know nothing about it... then you get people asking them questions about the product, having not read the full original post...so you end up with multiple posts on the same subject, or people trying to out "scoop" one another, by doing nothing but a cut 'n paste job of a mass email pretty much all of us have signed up to already...

is it worthwhile tweaking the rules to stop this? as it seems to cause replication, and annoyance for several users (judging by the responses to some posts)...

The best thing for you to do is just report posts like this and we'll take a look. Tweaking the rules isn't going to stop anyone from posting.