I believe that Constant Contact is falsely promoting it is offering a free online store. I say this because the free service allows you to offer just 3 products and you must display a big advertisement for Constant Contact. Most retailers offer hundreds or thousands of products. A super small number of stores can offer just 3 products online. In addition, most stores don't want a big advertisement at the bottom of their website. Yet, if one were to visit Contact Contact's website services page, it's constantly mentioning how 'free' it is. Showing ads isn't providing a free service. It's an alternate form of charging you and your customer's: it's charging you time spent look at its advertisements.
If a seller wishes to offer four to 10 items online, it's $12/month. Then, if it wishes to add an 11th item, the cost jumps to double: $24/month. This pricing strategy allows too few items, and too quickly jumps from tier to tier.
I suggest that Constant Contact make its website plans more appealing, and use the service as a loss leader to grow its email marketing business.