A later specimen of the cheating housewives spam had a site that was still active, so I was able to go find out the scoop. It turns out

Some married Woman feel they need more than they are getting at home. The Internet is great way to meet local woman who are looking for discreet sexual encounters with local men in their cities. No Strings attached! These ladies are ready and willing to meet right now. They don’t play games. They know what they are looking for they don’t play!!

And

For just $1 you will get full access to our entire horny house wives data base.

They also claim to have loads of adult content available for members, and even if you’re not a member, they’ll send you, "100% FREE PASSWORD SITES IN YOUR EMAIL… NO SPAM JUST FREE PASSWORDS TO TOP ADULT WEBSITES!!" if you’ll just give them your email address.
Somewhat closer reading reveals that the $1 is for a one-day pass to the site. I’m a little surprised that it consistently purports to be a dating site, though I’m guessing they make most of their money selling email addresses.