I've heard from some SEM guys that you don't need to be able to program to be successful in SEM. Just write good relevant ads and target long-tail, relevant keywords, and earn a high CTR for a high QS to lower your costs.
This is really only half the equation. The other half is the landing page. Not only is this an important factor in QS, but will, more importantly, determine the Conversion Rate. So, if you are working with a client and you notice a low conversion rate that is hiking up your Cost/Conversion, the only way out of this is to change what your users see when they click on your relevant ad (assuming the ad is as relevant as can be).
So in my case, my business sells private health services to various locations and in one location we receive a very high CTR by featuring the doctor's name in the ad description. However, the landing page has always been the home page. Thus there is an immediate disorientation for the visitor when they see a homepage that features 3 doctors instead of 1.
So it's kind of an uphill battle if you are dealing with a customer base that responds to the trust of a "PhD" title in the ad but the actual landing page (the brand, the hospital, etc) does not target the same doctor. Sure, there is an About Us for the doctor but I wouldn't send my visitors there.