I belong to a handful of both hotel and airline programs, and the ease of earning points in some, as well as the difficulty of earning points in others, is really striking to me. Some companies, it seems to me, shower you in points for doing nothing more than clicking on something, while others are extremely reluctant to give you points for anything but stays. So what are your impressions - which programs are the easiest to earn points in (besides earning base points by staying/traveling?) Which ones are the hardest - i.e. the ones that don't give you points for anything besides staying/traveling, and where you can't get points almost any other way?

My impression is that IHG is by far the easiest. In the past month, I think I got about 5 different bonuses - granted, they were 500-1000 points each, but that's in a MONTH. Coupled with the fact that they sell points via e-rewards and their credit card, I'm practically drowning in IHG points. Marriott is harder because they don't give so many bonuses, but they let you tweet. Meanwhile, Delta doesn't give you miles for anything but flying, pretty much (okay, they have a credit card, but given the value of skymles it's not really that good a value).

Maybe this is a redundant thread given that this entire forum is dedicated to how to maximize earning miles, but it seems interesting to me that there is such a huge discrepancy in how easily some programs award miles as opposed to others.