For my current biz model this poll is difficult to answer. Mainly, my earnings are the results of good SEO, which takes time to become effective. Yes I spend on hosting, domains, and other SEO related costs, but it's difficult to figure this on a daily or even monthly basis. It may take me 3 months to get there, but if I spend $500 to SEO a site, I'll generally make that back in a couple of days once it's ranked successfully, and then it's almost all profit.
If you're doing PPC, it's fairly easy to track your success on a daily or even hourly basis I guess.
If I add up all of my revenue for the month, minus all expenses, I'm probably in the 800% ROI range somewhere. I can live with that.
This is why polls suck cack.