Going against the grain here, I wouldn't automatically say yes, but I wouldn't say no either. From what I've heard in the local indie bookstore scene, manga is the number one thing that gets shoplifted, and that's not even taking into account "hobotaku", the people who sit in front of the bookshelf, read manga like they were in a library, and get really bitchy when told not to.
Yes, manga are comics, and it will bring diversity to the store, but it may not be profitable for the owner, and might even bring in a crowd they don't want. I would also recommend more seinen/josei type comics like Borzoi_Feet suggested, as their readers seem a little more courteous than your average One Piece/Naruto fan. They're also something that American comics readers are more likely to get into than straight shonen/shojo.