Google Adwords costing for landing pages

I have been doing a bit of work optimizing a client of mines website recently, to improve it's Adwords compatibility. I had noticed a slight drop in the amount of click throughs it was getting as well as an increase in the pay per click amounts for some of the keywords, so I thought I had better do something about it.

Everyone seems to be commenting on Google Slaps and SEO techniques recently, and I had paid minimal attention up until this point as I believe that if you create a site with good intentions and don't "overdo" the SEO for search engines, then you can't really go wrong... or can you?

I made sure that there was a moderate amount of keyword rich content on the home page to do with the subject at hand - urinary incontinence - and pitched the adwords campaigns similarly by split-testing certain ads in small groups according to seperate keywords.

I was quite happy with the fact that the new Google tool that shows quality of keywords for the destination page of the ad was showing "Great" for the keywords urinary incontinence and stress incontinence, but somewhere in the last couple of weeks, the minimum bid price went from 0.08 to 0.22 - and with it went the quality... down to "OK".

Today I spent some time craeting new landing pages to counter this, by basically taking the home page and recreating the copy to suit each keyword combination from my split-testing, and pointing the associated keyword to that individual page, instead of simply at the home page. I am a little concerned about the duplicate content rule that seems to be in play with the Google algorhythm, but I guess time will tell if I have made the right move.

The client is definitely happy with the amount of movement traffic-wise there has been up till this point, given that sales have increased.