The most expensive AdWords legal keywords in the US usually aren't as high as reported.
Headlines purporting astronomical cost-per-clicks make for great "internet bait."
For example, when ClickZ's Chris Lake published their top 100 most expensive U.S. keywords, it generated some decent social buzz and even some links.
After all, "$935 for a single click?" Wow!
However, there's little question that legal AdWords clicks can be expensive, it's worth understanding a few things about how this data is derived and the factors that contribute to the actual cost-per-click (CPC) that a lawyer is likely to pay.
TL;DR: Legal CPCs can be much lower than these reports if you know what you're doing.
Why Are Legal CPCs So High?
If you're completely unfamiliar with how AdWords works, check out our post on the AdWords auction first.
Generally speaking, lawyers (particularly personal injury lawyers) are willing to pay a lot of money per click on AdWords because of the high value of the fees that they are able to obtain from a significant injury case.
For example, if a lawyer spends $100,000 on AdWords with an average cost-per-click of $100, they can purchase 1,000 highly-targeted click from users who are searching for their services. If only one percent of those clicks leads to an inquiry from a potential client, that equals one-hundred potential client inquiries. If only one percent of those inquiries turns into a case with a $200,000 fee, the lawyer has realized a return on ad spend (ROAS) of 200%.
Obviously, any given campaign can perform much better or a lot worse than this example. But it's a good starting point for understanding why legal CPCs can reach such heights.
However, there are a variety of reasons why the CPCs that you ought to pay can be wildly different from the typical most expensive keyword post.
First, many lawyers tend to overpay for keywords. Some lawyers who manage their own AdWords campaigns simply have no idea what they're doing. They'll do things like broad match to legal terms (i.e. lawyer, attorney, etc). They'll set their maximum CPC (the most they're willing to pay for a click) with the intent to maintain an average number one position. Sometimes this is can be attributed to inexperience. Other times, to ego. Whatever the reasons, in my experience auditing legal PPC campaigns, bids are set without much regard to conversion.
To be fair, it isn't always the lawyers who are unnecessarily driving the costs of clicks. Many paid search management agencies are compensated on percent of ad spend basis. This means that they are paid a fee based on the amount of money their lawyer-client spends on AdWords. Therefore, the more money they persuade their client to spend on AdWords, the higher their fee.
This arrangement isn't inherently wrong, but the agency must be held accountable for delivering meaningful results to the firm. Typically, this should in terms of things like return on ad spend, cost-per-client or some other meaningful business metric.
Second, if you read our AdWords auction post, you know that there are a variety of other factors that contribute to the actual cost-per-click in any given account. For example, your Quality Score can have a significant on your actual cost-per-click. These factors typically aren't accurately reflected in the average most expensive keyword post.
In other words, by improving Quality Score factors, you can greatly decrease the amount you pay per click in your AdWords campaigns.
Third, many most expensive keyword posts aren't reporting actual campaign data. Instead, they are reporting from tools that attempt to predict cost per clicks. For example, the ClickZ post appears to have used a dataset provided by SEMrush.

Now don't misunderstand me. I'm not specifically calling-out ClickZ or SEMrush here. Without access to specific campaign data, tools like SEMrush serve to give advertisers a general sense of advertising trends. However, in my experience, most of these tools can be markedly different when compared to actual campaign data. Cost-per-click happens to be one area where the data is particularly inaccurate.
In any event, lawyers ought to be cautious in relying on posts like this to benchmark the performance of their own campaigns. Ultimately, as with any advertising, AdWords performance must be measured in terms of meaningful goals. Usually, they should be somehow connected to fees specifically generated from the campaign. If your campaigns aren't delivering fees at target multiples above your ad spend, you should probably get someone to give you a second opinion.