Marcia - I am not familiar with it. Do you have any other information?
I will speak generically....I would be very doubtful if its worth it.
eCommerce is not easy. You need a lot of website traffic to even get people to look at the products, let alone convert to sales - its not as easy as it sounds.
Ranking well in search engines is not an easy task to pick up traffic from there.
There are some already big payers in the market - esp foot.com and Footsmart - look at the the list here:
http://www.dmoz.org/Shopping/Health/Feet/ which is nothing more than a sample (on top of that list there are >70 other sites waiting to be reviewed and added to the list) (DMOZ is the webs largest directory of websites)
IMHO, if your website gets less than a few hundred unique visitors (NOT hits) a day, there is no way its worth it. If you get more than a few thousand uniques, then maybe consider it. (Most podiatry sites do not come close to this). I say this as to offer products on your site, you are competing with all of the "big boys" who rank well on search engines for a whole range of keywords and optimizing sites to do this is a big challenge. So either you go head to head with these people or you capitalize on traffic you already get, and you need a lot ---
I made comments on search engines and ranking in this
thread