I'm assuming you're talking about
http://www.i-soldit.com There are others as well.
The numbers I saw didn't look very good. At least for the franchise. I'd look into doing on your own out of a garage selling stuff you bought yourself at yard sales rather than selling on commission...
I did a spreadsheet on it, given the markup/commission, etc. According to my numbers, if you were to pay the rent and try to actually make a living beyond what you'd make doing retail, you'd have to turn over like 45-50 auctions a day, each for at least ~$40.00. (remember, your commission is a fraction of the $40).
Given that every item had to be photographed and a written description produced, that meant that, in an 8 hour day you'd have to "process" an auction every 10 minutes.
That means you'd have to receive the item (talk the person into selling it with you), photograph it, write up the description, tag it, put it on the shelf, box it, label it and ship it.
That's a lot to do in 10 minutes. Software and batch processing will save time, but ultimately, the only way the thing would 'work' is if you could generate enough volume to go way beyond 50 $40 auctions a day, and afford to hire someone for fairly low wages to do a lot of the work for you.
OF COURSE, it would be possible to combine an 'isoldit' franchise with other activities in the store-space, and sell you own, purchased things as well. Personally, this latter angle was the only way I saw the thing working...