Yes, probably. Those sites seems to attract SE traffic which is one of best traffic types to convert into sales. But, many people will find enough jerk off material there for free, so at the end, it is good question where you would put this type of site on scale of profitability. One is for sure, it takes lots time (like everything else). I've started
www.nylonstockingstube.com recently, it made some sales, but never find time to make sitemaps to submit to SE, do good banner exchange, and advertising campaign. It simply take too much time that I don't have so I will probably sell it if I see that I can't find time to work on this site, as I didn't until now. So at the end, It is probably worth of effort, but you must have enough time before start making money more serious and it is up to you to decide will you use that time into something else.