I use MongoHQ and think they are really wonderful. Great customer service and always helpful. Even if my startup grows to millions of users I would still get th

I use MongoHQ and think they are really wonderful. Great customer service and always helpful. Even if my startup grows to millions of users I would still get them to manage my DB. Plus I like their admin/stats tools even if a bit basic. Because frankly the DB is the part of the stack that does the least to differentiate me from the competition. So my efforts are frankly better spent elsewhere. Anyway I typically get around 200ms per request. If you are a typical website though I would be trying to get that 500MB of user data right at the front with Nginx/Lua/Redis.