Originally Posted by zoobird
Is it possible that that would cause such low quality scores, or are there any other possibilities?
If you really want to make money from PPC you need to make multiple landing pages on your site. These are pages that match A) The searchers intent and B) What you said in the ad. Those will give you a better quality score and you'll get higher conversion rates. Basically you want to carry through the message of your PPC ad onto your landing page. If your ad says 15 day free trial, your landing page headline should say something about the 15 day free trial.
They have 2 free webinars a month and tons of optimization examples on their site.
And to run your tests, google website optimizer is probably the best free tool out there.
The more focused you get the higher your profits will be. So instead of 1 login page (which I'm sure converts like poop) you should probably have 20-30 different pages tailored to your ad groups. Ideally you'd have 1 adgroup with 1 keyword phrase and 1 matching landing page but that quickly becomes a scalability issue.
At work we're up to about 400 landing pages but we use some software that automatically A/B tests pages and makes creating pages pretty fast (but it's like $4,000 a month for the software).