With the recent AdWords changes, when I tried to run these types of ads, AdWords wanted 20-30 cents to activate some of these keywords. If I ran the keywords at 30 cents, I had to constantly monitor them to see if I could lower the bid. Now these typically are keywords without a lot of competition, maybe 2 or 3 other ads. So I didn't necessarily want first position and to pay for that option. By turning the budget optimizer on with a maximum click of 30 cents, I could start a new ad and the most popular keywords would start near that maximum. If the keyword had a good CTR, then the budget optimizer would constantly drop the CPC for those keywords. Some dropped to a nickel or less, some in the dime range, and some never dropped. Those that didn't drop had an CTR that was too low and I'd then disable those keywords. Those that did well were now running as cheap as I could get them.
I do see an occasional problem with new ads, though. I'll put a new ad in the campaign and it won't run the ads saying I must bid 20 cents to activate the keyword. Well, the budget optimizer is set for a maximum of 30 cents, so run the damn ad already! I've tried changing the maximum click by a penny or so and sometimes they start running. I can't tell if those two actions are related though.
[edited by: eWhisper at 1:19 pm (utc) on Nov. 11, 2005]
[edit reason] Please don't drop names. [/edit]
However, for my accounts with expensive ($5 to $25) keywords, or for which there is a lot of competition for ad placement, or for words that are difficult to keep active at a particular price point, the Budget Optimizer really doesn't work so well.