A minor change like adding a character can go a long way in inceasing the CTR of a performing ad to make it perform really well.
Do you have a targeted and relevant ad for every keyword that you bid on?
Do you use Dynamic Keywords?
Are you putting a broad match for all the keywords? Do you use “Phrase” or “Exact” Match” where it fits?
Have you removed ‘negative keywords’ or those that invite unnecessary traffic to your site?
Is the Landing page (the page that you want visitors to come to when they click on the ad) full of quality information, rich in keywords, and does it relate specifically to the offer featured in the ad ?
To get results with your published ads fine-tune the Adwords campaign on a daily basis. If you are not doing this then maybe it is time to outsource management of your adwords campaign!!