I think that when it comes to the adult industry, one of the most underrated areas of pleasure is in the mind control erotic stories niche. For that reason, I have to give my hand to MCStories.com for maintaining a fantastic database of erotic texts for you to look through and read. If you thought that Fifty Shades was the be-all and end-all of erotica, think again.
MC Stories is a mind-control story archive, which means you'll find fantasy tales of people who have been coerced through hypnosis to do things that they might not agree to otherwise. Naturally, I should provide a disclaimer here that these are for the purposes of pleasure only, and any desire to perform mind control sex acts is likely not a step in the moral direction.
The stories are sorted into different organised lists such as titles, authors, story categories and readers' picks. There seems to be around 10,000 erotica tales in the archive, so naturally if this is your niche, I can't imagine a better place to find what you want.