I discovered yesterday a new way dodgy sellers are finding of circumventing Flippa rules and exploiting less experienced buyers.
They create their listing and are careful to follow all the listing rules. Wild claims, claims about originality on content, guarantees about future rankings etc., are kept out of the listing to make the listing look very legit.
But they've got the copy all carefully prepared - copy that makes all the above claims to hoodwink n00bs - and they send it by PM as soon as you bid or show any interest. In fact, you have to PM them as they usually leave out one crucial bit of information or make a blatant typo to tempt the private contact.
Some of them have gone one step further and withheld their URL behind a Confidential Listing requiring you to sign up to their NDA and, bingo, they can now PM you the FAQ.
Flippa, you won't find these sellers by going through my own private PMs at Flippa. I was given a login to someone else's account to see this yesterday.
Caveat Emptor, but when the emptors being encouraged to bid in Flippa are raw n00bs then Venditor Praemium.