For anyone that thinks this totally comes out of nowhere, it sure doesn't. This business model has been around for a while already in more women-centric industries with handmade goods, cosmetics, and so forth. Here's an example:
GRANTED this is probably not at all the way that the average BPL member 'discovers' worthwhile gear items. But, I was just saying, in quiet defense of the OP, that it's not like this concept comes directly from another planet.
Again, this will probably be irrelevant for most of us, who would prefer to read reviews and understand the design and performance of a product before we pay for it :-)
The business model really applies better to people that just want to get "fresh" new interesting little gear and doodads. For them, SummitStash would be great. E.g. the average customer at REI, like many of my outdoorsy friends that I've taken backpacking ... they will probably eat this up. Whether acquiring more stuff on a monthly basis will be to their benefit, that is another question entirely :-)