I'd say it's a niche within a niche. As far as sales, I'm not sure. Those types of comics are very popular in certain parts of the world though.
i tend to agree
I do a title called "City Hare" and my experience with the erotic content is that it tends to get rejected by most shops.
Typically, when I've gone to comic book retail shops to carry "City Hare" or even "The Planet", the owners of the shop have refused to carry it based on their "graphic" content. They were concerned that a little kid would get their hands on it and have their world completely destroyed. "City Hare" contains very little erotic content, same with "The Planet", but those couple of pages stand out to the shop owners. I'm not sure if it's because I'm Black or if it's because I'm not popular enough. They do, for instance, carry works by Robert Crumb and I think I even saw "Lost Girls" in there once.
Here's a taste of "City Hare" down below:
City Hare-ISH 6-Ayo 4 Yayo