I think the trick is variety. I omade a 150$ order from ehobbyasia yesterday. Originally, I was on eBay, looking for a 20$ VSR-10 laylax spring.
The search came up with ehobbyasia so I bought the spring from them and then went on to scan the rest of their gear to do one single big order.
I ended up buying a gun bag, a tightbore barrel, 1 more spring and some kind of pouch.
Because ehobbyasia had variety, I ended up buying more then I was expecting (so what else is new).
Good lesson learned. Attract people with some basic stuff and make them spend a lot with a good variety of other gear and parts.