Why not? I've been doing small business sites for people locally for awhile now and it's easy money. You'd be surprised at the number of small biz places that would love to have a site and will jump at the chance if they have someone to do it for them or walk them through it step by step.
Most of the people I've dealt with want someone to do everything- hosting, domain, setting it up, updates, etc. But a lot of places probably have at least one employee who would be functional enough to set up some easy BS like this.
There's probably some kind of easy add-on shopping cart/payment deal that Sam's is profiting from, as well. Or once they get it set up, they find out they can only sell Sam's products and there's an extra fee for everything else.
