This is an interesting article regarding dynamic keyword insertion in your Google Adwords advertisement.
When we deploy Dynamic Keyword Insertion, every time someone types in the exact search term you are targeting, your advertisement would include those keyword – in bold – on your advertisement.
With effective php coding and htaccess along with some modification in your Adword unit, you can increase your traffic through Adword program.
More details on Google Adwords Dynamic Keyword Insertion click here
Dynamic keyword insertion in AdWords URLs for higher click throughs
Search Engine Optimisation techniques