A very nice suggestion, you have given to me, Now It's clear and I will work on it, then will let you know, what I am facing and what I have to do. Actually I have seen various campaign, where with a particular set keywords - models are changed dynamically. Ok I explain you more. Suppose I have a site which is selling chocolate in various flavors. Now the ad would be - chocolate keywords would be fixed for any flavor and in front of that the flavor will be changed like as chocolate strawberry, chocolate fruit n nut etc. or it may be preceding also as milk chocolate etc. Such like this I have explained you the "Camera Keyword" with various models changed in front of that.
Using your targeted keywords also in description, that's ok, but I actually want to know changing my some keywords dynamically with my one fixed keyword. As I have told you before suppose the keyword "Camera" is fixed or any particular company name model is fixed like as "Nikon". Now I want, after Nikon keyword my other various models of nikon would be changed dynamically like as Nikon F2 photomic A, Nikon F2 photomic AS, Nikon DSLR D35, Nikon DSLR D3000 etc. I want suggestion on this actually.
That chocolate example sounds vaguely familiar... You've asked this before, no? Same thing here. Different groups for different flavors of chocolate. Someone is looking for and searches on "chocolate strawberry". Bam. That keyword in your Strawberry group fires. Your ad shows strawberry. Why would you want to show an ad about chocolate nuts? You are trying to be lazy. You want a generic ad with the different model of camera or flavor of chocolate to appear in your ad. You want to bid on "camera" or "chocolate" and let the system insert the proper model depending on what the search is. Doesn't work that way. Wouldn't work anyway. What if I type a model of camera you don't have? What if I search on "where to fix my Brand X camera"? What landing page would you use? You have to make that happen. You have to create different groups by bidding on the exact keywords, not generic ones. The more precisely you do that, and the proper landing page, not a generic home page, the better it will be for you with good conversions. That means a better ROI, more profits to you. It work but worth it.
I will plan to make it exact, but actually I have seen my ads using dynamic keyword insertion and after every search, if search related to them, their ad display always changed. If I go for exact keyword placement for my PPC, I know there is a facility and I can insert up to 20 exact keywords in the ad, I think that will rotate automatically. But actually this thing is not cleared still in my mind to use the dynamic keyword insertion in your PPC ad display and no doubt mostly are using this thing in their campaign.