Moving forward I will be adding items to the USMB store from my company RetroRoo as well as our company logo to the banner on the site. This will not be invasive as I know how you all feel about ads and frankly I feel the same way about them.
If there is a product that you think we can get and you want it added to the store please by all means ask. I am all about making this a positive thing for you guys and my shop and not here to make a fortune but I do need to recoup the costs and keep the site free to use.
USMB swag would be more universal. I live half-way across the country from your shop and that is a lot closer than many of our esteemed members. Nothing against your shop, I just relate to USMB, whereas I have never been to your shop and it's 1,500 miles away. I could use a heavy-duty USMB tote bag as reusable grocery bags That way they could be printed to order and wouldn't create overhead costs.
Also, we have a lot of creative members on here with huge range of skills and abilities. Perhaps some of them would like to make USMB products to sell on your site and you could charge a percentage. I am having a mental block as to what that is called (con....something) when a shop allows people to sell in their store for a percentage of the purchase price. It could even be in limited runs. Say member such-and-such did a run of 10 USMB billet aluminum shift knobs for ea81s, you could provide the marketplace for a strange and unique cottage industry of Subaru accessories. I paid $55 a pair for aluminum rear hatch window latches for example. Instead of advertising external business interests you could have banner announcements of USMB and RetroRoo products, especially if they are limited run items. I think that would also give the site more of a member-involved feel, but talk is cheap and easy and it might be more of a hassle than it's worth.
Years ago I tried a garage sale kind of approach to donation by advertising things I own for sale, but the purchase price was a donation to USMB. I got limited response at the time (possibly because of what I was offering), but most people that made commentary thought it was a good idea. If you could think of a way to facilitate people donating in that manner, then I think it would be easier for people to donate, especially members that don't have a lot of extra cash. Again, it might more hassle than it's worth, but I think there are creative ways to generate monetary support beyond just cash donation.