I've never failed to notice that religion is as much about power and influence as it is spirituality. I find it interesting that devout believers are staring to hint at such even if it is half-hearted and frequently inadvertent. David Gibson's "Catholic gift stores see a (papal) bull market" is decent example. Even though he is focused on the Roman Catholic church most of what can be read between the lines applies to all religions.
I have been to numerous religious sites and not one lacked some sort of gift shop or vendors area. The money these places generate is certainly nothing to scoff at but even that isn't the only dubious aspect of them. The cheap frivolous trinkets and doo-dads, most that have nothing to with anything, are a nice symbol for the faith that hawks them. They tend to be as devoid of substance as the religion. They are simply a means to create a false sense of connection to something greater. In a way, it is a win-win scenario for the sect/denomination that sells them. They get the financial benefit and manage to exert more influence, if somewhat subtle, over their patrons.
I have no way to prove it but I am reasonably sure that many purchases at these sites have more to do with a sense of emotional obligation than any genuine desire to have the items. Much of what gets sold when never be purchased outside a religious venue/context. To some degree this is true of most products at any "tourist trap." However, he religion adds emphasis and acts as a reinforcement to a disturbing type of "brand" loyalty.