You know what I can't stand? When websites, businesses, blogs, etc. reward someone for being the xx number of something.
For example, you see the "Be our 100th fan on Facebook and we will send you a gift card!" kind of thing.
You know why I can't stand it? Because it craps all over the people that made you popular in the first place. Only bandwagoners are rewarded in that scenario.
How about doing a real contest where you do something to drive your revenue? Or reward ALL of your readers/customers with a promotion once you get to that number?
Kind of like the guy who won a $10,000 gift card to iTunes for being the billionth download....it only serves to make the rest of the people who spend their hard earned time or money feel like they didn't really count any more than the schlub who got there late.