Wow another 2 new blocks mined here. It's good pool.. I recomemded increase the fee to 1% or 1.5% because u need to pay the servers..
Or 10 %! How about 20?
Or keep it the same and keep attracting a higher quantity of users. Economics 101. More users = more blocks = more $$$ for monthly server fees, though in reality one block/month should cover server fees entirely. Servers aren't crazy expensive. $150/month will buy you two very nice servers with alot of features or three good servers with bare-bones features and you add what you want from there.
It's the McDonalds template. You can't raise prices without losing business. I think he hit the sweet spot with 0.5%. It was a stroke of marketing genius.