Those are advertised as memberships though. People know memberships have recurring billing. The acai and similar rebills are marketed to resemble a one time purchase, with the rebill information tucked away where people will be least likely to notice it. I just think that somebody, no matter if it's their own fault for being stupid, who has ordered a "free trial" and then has a surprise $80 credit card charge, will be far less likely to trust any trial offer on the internet in the future, even the ones that really are just trials. They might avoid internet purchases altogether.
http://i44.tinypic.com/ydrus.png
I can totally see how the average self-employed trial hunter will notice right away that's it's a membership. Yup. "FREE Shipping" with a tiny asterisk, "Just $1.99 per movie", and a tiny "*with membership" make it pretty obvious. You gotta be a moron to think otherwise. Oh wait.
But no, you are right of course, it's marketed as a membership and it's made very clear to customers. That's the difference between the scammy free trial rebills like acai and biz opp and reputable companies like Disney and Columbia House DVD that play by the book and make these terms very clear. It's things like these, and lost/unwanted shipments, problems canceling or getting their money back that plague the industry.
Surprise, surprise, dumb people are dumb. And you are so off base with your assessment of the average joe, it's not even funny. Someone signing up for these free trial offers is FAR more likely to sign up for one after another, than he is to learn his lesson and actually bother to read terms and think for a second before pulling out his credit card. And why would he, asking the merchant whether his site is legit, because he has been scammed in the past is so much easier than turning ones head and reading that boring part of text. Worst case, one can always complain online. Sometimes I believe these people only do it to get interviewed by ABC.