You can't win the best you can hope for is to make a little more than you spend. If you increase your bids to get up higher on the page you get crazy calls. Calls like people trying to sell you something and they cost you money by clicking your ad. You get clicks from web hosts trying to boost their income. Sometimes old people call trying to reach someone else because your ad is on a page and they can't tell what a sponsored link is. If your ad is # 4 on the list you get clicked on by accident by people scrolling down the page. Google says you don't get charged for these clicks but how can the separate them from real ones?
If you don't advertise the real customers can't find you.
As long as your reading this I would like to mention, you bid on ads to be placed but ,they are in control of the price more than you know. I can bid on a page with no ads or ads out of season like air conditioner repair and they will say my bid is to low to be on the first page when there isn't any ads. And the air conditioner ads in the winter still start over $10 a click in winter.
I ready think the partner display ads are the worst I get clicked on from them a lot with no calls. I think they click them so google pays them.