When you buy a keyword at a search engine, you’re buying into reaching an audience of people who have expressed interest in that keyword. This is like the List Management business.
When you rent a list, you also buy into a pile of people who have something in common. It could be a trade magazine, or a list of people who’ve bought from a sporting goods catalog like L.L. Bean. In both cases, you’ve accessed people who have raised their hands and expressed interest.
So buying keywords is essentially the dynamic list business. Just like its postal counterpart, most people won’t respond to you. But in those relative few who do lies your opportunity.
In order to optimize the small number who responds to you, and to also qualify those responders, dogged testing is needed. My observation is that testing at the search engines is easier, simpler, and much faster than testing in the physical world. Clickthroughs loosely equal the amount of people who’ll open your envelope. You can think of your keyword buy as your outer envelope copy, except you’ll have a tighter read on how many people do click through versus how many open envelopes.
Not all clickthroughs are created equal. Some keywords will bring you much traffic and little or no money, while others hopefully will bring you money and maybe less traffic.
The key is to track which keywords pay off for you at the back end. Test, test, test. LC