You’ll certainly have an affair if you only sign up for one site but it will likely take longer to get it going and once it’s over you’ll likely have to wait longer to find another partner.
The sites worth visiting get more in depth reviews at Affairs Handbook (those not really worth your time get reviewed but it’s a little shorter) and they need to fulfill the five requirements I’ve laid out before they can be considered a safe bet for a great affair.
The first requirement is also the most important: The site has to have real members, not a bevy of fake profiles. Some are from private detectives hired by spouses or simply looking for cheaters so they can blackmail you (that actually happens; if you report the blackmail you have to admit to looking for an affair so most guys just pay the relatively small amount the PI wants), some are escorts looking to get desperate guys to pay them, and some are just guys posing as girls and messing around (those are weird and annoying).
When people are on the hunt for an affair they don’t care nearly as much about things like how much money you make, how good a person you are, whether you like dogs, etc.
It’s mostly about looks and charm and there’s going to be competition so you have to put out feelers in as many places as possible, which is why it pays off to sign up for multiple sites.
If you’re on one site then you’re limited only to the men and women that have signed up there looking for affairs.
You could double your potential dates by signing up for another site and the more you join the more people you can contact and the more sex you can be having.
After a great deal of experimentation and experience it’s clear that the best way to ensure an affair and a great time is to sign up for multiple sites.