Never again monetization strategy

What monetization strategy have you tried that you will never try again?

Not all monetization strategies work out for forums and blogs. You might try one that works really well and stick to it. You might find one that doesn't work at all with no plans to try it again in the future because, you just know.

It's good to "shop around" though and try many, right?

What ones have you tried that didn't work out and you will not try them again? Why is this?

I will never do aggressive ads again. I tried it once and the forum just felt dirty. users complained, bounce rate jumped. Ads can be very intrusive and they can begin to drag the space with the users.