One thing I've noticed in both my SEO efforts and in PPC advertising is the difference between general and specific keywords. By getting a feel for the value of different keywords, you can make better judgments about how much to bid for them on AdWords. To make this as concrete as possible, I'll describe it in the context of my own business.

I'm a lawyer. My law firm, based in Albany NY, handles criminal defense (including traffic tickets and DWI) and personal injury (including car accidents). One high-volume general keyword that relates to our business is speeding ticket. Another is car accident.

So now imagine someone comes to my website having searched for the phrase "speeding."  There's a good chance the searcher got a speeding ticket, so it's a potential prospect. But did they get a ticket or is the search about something else? If a ticket, where did they get it? Is it somewhere I handle or somewhere I don't? And are they thinking about hiring a lawyer to help with their ticket or are they just looking for information and/or free advice?

Now consider someone who searched for "traffic lawyer in Albany NY." That is a prime prospect. I want that user to find my website. He's looking for what I do in the place where I do it.

Take another example. Someone searches for "car crashes." Was she in a car crash or is she just looking for information about them? Why did she use the plural "crashes" instead of "crash"? And is crash the term you would use when looking for a lawyer for a case like this? I tend to think people would use the word "accident" instead of "crash," but I could be wrong.

Now consider the specific scenario - a search for "Albany NY car accident lawyer." Like the first example, this looks pretty good. Now suppose they used the plural "lawyers" instead of the singular "lawyer." Maybe the person using the plural is more likely to be shopping around and looking at multiple lawyers, where the person using the singular is shopping less and just looking to find someone competent.

Consider a variation on the general. What if someone searches for "lawyer"? Well, they might be looking for me, but there's a lot of different kinds of lawyers in a lot of different places. There's a lot of things I don't handle, like bankruptcy, divorce, and patents. If they search for "albany lawyer" they'll find me, but what kind of lawyer do they want? If they search for "accident lawyer" that's the right topic, but do they need one in my area or somewhere else?

With AdWords you can use geographic targeting and negative keywords to tune these things but you will still get some clicks that are not for your location. It's hard to tighten up your ads to eliminate all the bad clicks without losing some good ones.

There are also gray areas in the middle - someone searches for "defense lawyer," for example. That's better, but are they looking for a criminal defense lawyer or maybe a defense lawyer for a civil case? Someone searching for "personal injury lawyer" might have a medical malpractice case, and I usually don't handle those. Or what if the search includes the word "Albany" but is really about another Albany. There are other placenames with that word in California, Georgia, Indiana (New Albany) and more.

Of course, the best thing is to have good organic SEO. We've done that pretty well with our site. But the value of specific keywords still matters, even for organic SEO.

Coming back to the question of value, how much more is the specific keyword worth? One of the challenges in our business is that it's hard to measure conversions. We don't have enough volume to have reliable numbers. Also, a substantial number of clients hire us after leaving the site and coming back. In our business it is unusual for someone to buy without speaking to us first. On the return trip they rarely come from the same keyword search.

My best selling keyword phrases are variations of my own name. And I'm not famous. The client finds our site somehow, calls us, and then finds us again by going directly to our site or by Googling my name. I have yet to find an Analytics package that can track that visit back to the first time it came to our site so we can see what keyword brought them in. Other statistics, like pages per visit might be helpful, but it's still not easy.

So in the end you have to make this value decision based on your gut. My gut tells me that the very specific keywords are worth at least five times as much as the general keyword, and perhaps ten times as much. It's mentally challenging to put that into practice. Bids on the general keywords tend to be too high, and the cost of bidding high enough on the specific keywords can be shocking.

What do you think? How does the general vs. specific issue play out in your business, and what do you do about it? Comments encouraged.