You needed ten months to figure that out? Wow. If I were you I wouldn't have made this thread to be honest. If this is how average miners calculate, we can expect GPUs to still be running when Asics are ruling the hash rate.
Yeah, because I totally don't think about anything I ever do.
Why shouldn't I have made this thread? These are largely unconscious processes such that we don't usually notice them. And sometimes although we do notice them, we don't really care because we create a justifiable reason for not caring, one that's more powerful than money is.
Looking back, for me it was something along the lines of, "Why fix what ain't broke? I'm already pulling in steady profits." Keep in mind I don't pay for electricity as part of my rental agreement, so 8-10% larger payouts to me is NOT the same as 8-10% larger payouts to someone that pays for electricity.
If I'm reading through the forums and I click the "show unread posts since last visit" link and I see all these ads for "Need hashing power! 110% PPS!" or "120% PPS limited offer!" as I suspect you do too, why don't you continuously join these pools? Well, you need to trust them to a certain degree.
I trust Deepbit (still do) because a lot of people have been using them successfully. I was one of them and I grew to know that I could count on steady, regular payouts from Deepbit. I recently joined ABCPool for similar reasons...but the numbers are a lot prettier.
The thing is that the math is not ALL that matters -- whatever should mathematically bring you the greatest profits is not necessarily the best idea (BitScalper, anyone?). Trust is important too, and Deepbit has earned a lot of it.