We started using google adwords about 8 months ago! From what we were doing we were getting 15=20 clicks a day at around .40cpc a few days ago I wanted to do an experiment and see how many I could get if i jumped my max cpc and i put it at .75 for 3 days. It was good and we almost doubled our clicks. Then I went back down yesterday to where I was at .45 and now none of my ads will show up. The min to show up is now .65 at the lowest and about 1.25 for the highest. I have never paid that much for any of the keywords why all of a sudden are the costs sooo high? ANd today we only have 1 click total and we have NEVER had this problem If you could give me some advice on why this would do that and i doubt there is anything I can do to get them down but we need those clicks!!
If you were getting double the clicks at less than double the cost, why stop it? Also, you are looking at just one day. It also happens to be a weekend day on a long holiday weekend. You may have had much lower number of clicks on regular weekends, probably similar on holidays. So nothing I'd concern myself about just yet. One thing though. Increasing your CPC has given you a better position. Your QS got adjusted accordingly as you got impressions and clicks. With this new data, reducing the CPC and getting a minimum first page bid suggests your ads are not as good as the competition. While you don't say, I assume you tested only one or two ads in all that time, which is a mistake. Now you are seeing the true quality of your ad. You must try to improve it. For more on QS, see the Adwords FAQ.