You generally can't run 1 ad with 1000 keywords as you will pay out the ass. High quality score makes your clicks cheaper. I run say 4 ads in 1 campaign and 5 keywords. I then come back and see which keyword was the most successful or more clicks at less cost and which ad performed the best. Then I create a new ad with only the ad that performed and the keyword that was priced good. Relevant ad + relevant keyword positioned in the ad at a fair price equals success. Basically you need to find keywords that mean the same thing as the higher priced keywords but that have less competition for them. If you have everything good nice ad, cheaper keyword, high score then basically you could pay $1 click on a keyword where a very similar keyword may cost $4 click etc... Takes time & money to get the perfect formula figured out. Better off running 10 ads for individual keywords then trying to run 1 with 1000 keywords as you wont be able to keep the quality score up.
