They have been around long enough not to be a scam, however just be aware of how they make their money....and that is from you!
It all sounds wonderful, fully integrated shop stocked with fantastic products, but you will be paying for that shop, and if you are not selling stock.......then you will be going backwards in a big hurry!
I don't know their fee structure, but companies like this will usually charge you an establishment fee (set-up fee), then a monthly charge on top.
Make sure you go in with your eyes wide open if you are going to use a platform like this, know what your fees are going to be. You have to balance that against how much traffic you will be able to generate to your shop to create sales.