this process must be simplified for my own sanity and so that I don't waste the company's time and money by ultimately listing things that don't matter. let me know what you guys have to say.
Overture used to trot out a pretty good presentation of the online buying cycle. A couple of quick points it made was that low cost products involve less research, thus fewer searches. High end products often involve a 4 step search and you should target pages and keywords to each of those steps.
I can't quite remember the names they gave each of the steps, but the search would go from the very general to the very specific.
1) General information about a product or product family, how it works, features, etc.
2) Some comparison shopping among different brands, general product performance.
3) Starts narrowing search to specific makes and models, product reviews.
4) This is what I want to buy, searches for specific product numbers.
So, yeah, as the buying process winnows the searchers choices down, it would make sense that product number keyed ads would receive fewer hits. But you do want to target each phase of the cycle in order to keep your company's name in the searcher's face. Even if ads aren't clicked in the early phases they can still act as positive branding impressions when it comes to the buying phase.
A bit long winded and I probably left out some important points. Hopefully somebody else will come along to flesh it out a bit.
Ultimately, you probably want to test both general and specific ads, to see what pulls best.
Start by looking at the traffic reports from your non-PPC traffic, if you have access to it. You can get some idea of how people are searching (and finding) your products from those.