First of all - "Is the animal torture video business really THAT big?" shouldn't be the question. There aren't THAT many kiddie porn videos either. We make laws to protect the minority, not the majority. Secondly, wemake distinctions for  all sorts of random things. One can drive at 16, putting everyones lives at risk, but not vote for 2 more years. With that in mind, it seems totally possible to ban dog fighting videos while safe guarding commercial farming. With that in mind, right now I don't really see the down side to preventing the sale of videos showing the torture of animals for entertainment purposes.