I am considering using adwords to promote a forum of mine. Has anyone used adwords to promote a forum, and did you find it effective in getting more members and posts?
Of course, actually once adwords can promote any website; it will definitely promote your forum.. Just set out and try it yourself.
The goal with your forum would be to get conversions / registrations. So you want to set-up conversion tracking and then see how much each conversion is going to cost you. You want to work out how much every active member earns you per day / week / month and year and see how much you can spend on closing in a conversion and then see if you can optimize the campaign accordingly. If you head on over to Focused.org and start a thread there specifically to your forum, I'm sure I can help you step by step and expand on it.
Adwords tactic: Use placement ads to place your ads on your competitors forums/website. Make sure you think carefully about your marketing. Offer some sort of freebie or make a headline (or copy) that's a bit cheeky and makes fun of your competitor.