Some concepts are so fundamental, you assume everyone gets them right. Never assume anything when it comes to online advertising.
Bidding and the analysis that goes into fine tuning a flexible bidding system are critically important to a PPC program and are often neglected. Folks tend to spend too much time flipping copy, and not enough time studying the numbers. There is much more money to be made with the latter than with the former. I used to think the issue was simply not knowing what to with the numbers, but now I realize that some systems don't really give folks access to the raw numbers needed for meaningful analysis.
In any analysis, step 1 is "Gather the raw data". What happens if that data is hard to access, takes time and requires lots of manual manipulation to bring together in a useful format? The answer is obvious: not much analysis is going to take place.
Yet a number of professional SEM firms are in exactly this boat. Many SEM systems don't use the atomic (ad level) cost and click data from the engines. They use estimates, and periodically do data pulls from the engines for reports back to the client.
This came as a total shock to me. How could it be that big companies -- much much larger than us, who've been in this game longer than us -- not get this right?
If the sales data is on one server and the cost and click data is on another server doing the analyses that are critical to success becomes impossible. Pulling the data together should take moments, but will take hours if numbers have to come from different servers.
An important technical question to ask any prospective SEM agency is: Do you have an API connection with each engine, and if so, do you store the daily ad level costs on your server? If their answer is "no" and you're looking for first class results, you'll need to look elsewhere.