This deal has been going on, on select movies for a while. However it seemed to be better before. Or well it was better the last time I was there than when I went yesterday. The titles in the sale have changed (and personally I'm less interested in what's in it now); and, before some of the movies in the group were on sale so it was double savings...
So you were getting another $5 off a decent sale price making it a good deal. Now it seems even the movies that are on sale in the group aren't really that cheap (e.g. Simpsons for $35), while most of the others aren't on sale at all.
Anyway if more of the movies in the group come on sale or they add movies it might be good again.
An example of what I got before, just for reference...
Blood Diamond ($24.99) and Cruel Intentions ($23.99) IIRC, both on sale; subtract $5 from each made them $19.99 and $18.99, respectively. But when you have those movies at regular price, the $10 off doesn't work out as well.
