I've been wondering the same thing as the OP, and saw this thread.
Yes, wondering if there is one company behind a few sites. I've checked dateacuckold.com over the years, and recently looked at seekingcuckold.com, and similar to what someone else said, it seems like a lot of the profiles are the same, or they'll have the same write-up but a different picture.
I'm pretty sure that there is some fake profile creation going on here, meaning by the site itself. Even the towns members are supposedly from make no sense- half of them are from tiny towns you've never heard of, which doesn't seem realistic (if you have a group interested in a certain thing, then just like the general population, a lot should be from the big cities, the next group from the cities around a million, and so on, it doesn't stand to reason that a lot would be from places like Hamilton, Texas).
However, I have talked to a few members on dateacuckold.com who have been real. Of course, it's never easy to find the right person and even harder when trying to date in a small niche where there seem to be more men than women into it, but anyway there were some real people on that site. But there are very few active members on it.