They are not a scam,
but yes they will spam you.
When you sign up to their site,
you are agreeing to receive ads and promotions through your SMS text service and email.
They are getting your demographic information when you sign up and then delivering ads and offers to you that would interest you.
You can apparently opt out of the ads,
and I`m not sure how often they send you this kind of text marketing.
But you will be charged by your wireless carrier for the cost of
the text message.
Ventones probably gets a cut of that from the cell company.