Tradesy is a great overall concept and makes it easy to list items for sale, but you will not get any significant views (and therefore, sales) unless you refer lots of friends and family to the site through e-mails, Facebook, etc.
It is essentially a referral marketing firm. If you don't bring your personal contacts to the site you won't have your listings "loved", and therefore featured prominently for sale.
Items are not listed for potential buyers based on a basic search, but rather on popularity. "Loves" are generally achieved by you personally referring people to your items for sale and therefore to the Tradesy site.
There is nothing wrong with this business model as long as it is clearly stated up front on the site and in their marketing, which is isn't. Don't waste your time uploading items for sale unless you are also ready to enlist your personal contacts.