Perhaps it's the flexibility in their gender and relationship statuses—for instance, you can list yourself as 'attached' as well as 'looking' at the same time.
Verified, Schmerified Beware of the “verified” profiles that some sites tout.
Even some of the more clever fake profiles can get “verified” by using a friend’s credit card.
Unless the online dating site is going to go to the extra effort of meeting the single in person, doing a background check, and taking their online profile pictures for them (like Findthe It Factor.com, a personalized dating service), then “verified” means nothing more than the faker has access to a credit card.
There are services that can do background checks for you, if you feel the person is worth looking into further.
If a single you’ve contacted can’t answer basic questions, just gives you one or two-word answers, or gets angry that you’ve questioned if they’re legitimate or not, then move on.