Distribution of the 37M users on Ashley Madison

Geographic profile maps which are basically Internet users maps https://xkcd.com/1138/

This is a touchy subject and my statements are merely conjecture to kick off a discussion:

Given the greater proportion of males to females using the service, is it fair to infer that men are more likely to cheat, or more likely to premeditate the act of being unfaithful?

If the latter, and we assume both sexes are just as likely to cheat, for women it's more likely to be an impulsive act - one of passion - whereas for men it's a planned behavior.

Another hypothesis: men looking to cheat try all methods they can think of, including this, whereas women looking to cheat probably have success with the first method they try.

Because the top most attractive men may get a large percentage of all the women in a situation where relationships don't matter, so there are more men who can't find a match.

So in 3rd world countries there is pratically no cheating.

No, there are basically no people cheating on the Internet. Emphasis on the "people" and "Internet".

Or rather, not cheating on slashley scuzzin .com