As anyone with experience running paid search ads on Google should know, Google doesn't allow for double ad serving. Unfortunately, businesses, including law firms, get away with it more often than Google would like to admit.
What is Double Ad Serving?
Double ad serving happens when one advertiser tries to show more than one ad on a given search result page. Here is what Google says about it:
To protect the value and diversity of the ads running on Google, we don't generally permit advertisers to manage multiple accounts featuring the same business or keywords except in certain limited exceptions. Furthermore, Google doesn't permit multiple ads from the same or an affiliated company or person to appear on the same results page. We've found that pages with multiple text ads from the same company provide less relevant results and a lower quality experience for users. Over time, multiple ads from the same source also reduce overall advertiser performance and lower their return on investment.
Whether it's because Google isn't very good at enforcing this policy, or really doesn't care as much about protecting the value and diversity of the ads running on the platform as they claim, double ad serving occurs much more frequently than Google would like to let on.
Recently, while performing some competitive analysis for medical malpractice terms in Washington, DC, I noticed yet another example of double ad serving. In this case, it was being done on behalf of a local DC malpractice lawyer.
By setting the search results to the Washington, DC area, and performing a search for medical malpractice, I was served this page:

As you can see, the number one paid search ad is for wilsonlaw.com:

You will also notice another ad a little further down the page for the website: http://www.medical-malpractice-lawfirm.info/. Curiously, that ad appears to be another advertisement for the same lawyer:
Hmmm... That's interesting. The same advertiser, serving the same looking website on two separate domains, on the same results page. Looks to me like a clear violation of Google's double serving policy.
Should I Do This?
Like other issues involving lawyers and online marketing, many readers will look at this example and contemplate, whether this is something that they should be doing. My short answer is no, as it could jeopardize your ability to advertise on Google altogether.
But some will argue that this is an excellent way to "dominate" search engine results pages. In fact, it's my guess that the lawyer doesn't even realize that he's advertising in violation of Google Adword's policy.
In my humble opinion, each advertiser, whether doctor, lawyer, or plumber, needs to make an informed decision about how they advertise and market themselves. Further, specifically for lawyers, there are rules of professional conduct with which lawyers should comply.
Who is to Blame?
So who is to blame for non-compliant advertising? There appear to be three probably suspects: The lawyer-advertiser, the advertising/marketing company, and Google.
Unfortunately, in most cases, lawyers don't have the time, desire, or knowledge, to be able to make informed decisions about their online advertising and marketing. Obviously, this is no excuse for "bad advertising" practices and they are the ones ultimately accountable for their reputation and license. However, it seems that at least some blame must be attributed to their advertising/marketing agency.
As you've probably experienced elsewhere, many advertising and marketing companies aren't in the business of adhering to advertising rules, or lawyer rules of professional responsibility. And in fact, there are some lawyers who insist on gaming the system. So not all blame can be attributed to them either.
Finally, there's Google. Google's incentive is for their users to click on ads. That's how they make money. Do they have incentize to police violations of their policies? Sort of. They contend that if they don't maintain the integrity of the engine and the ad platform, people will search elsewhere. But since Google has become synonymous with search, it isn't realistic to think that people will abandon Google for these types of infractions. In fact, most users wouldn't even notice this form of double ad serving.
Does it Matter?
Undoubtedly, some readers will ask whether it even matters that advertisers participate in double ad serving. Which is a fair question. It's almost a victimless crime. The only groups that may suffer are users, who my be misled that there are more options on search result page than there actually are, and other advertisers who comply with the ad policies.
On the other hand, perhaps the advertiser is taking some risks too. There's a chance that they are penalized for double ad serving by Google. Additionally, they may take a reputational hit or even face ethical issues with their state bar.
Despite the competitive advantage it might provide, I strongly recommend that you don't double ad serve. It is one more reason to learn about online marketing and advertising before you dive in head first.
UPDATED: Was it an Accident?
It was suggested to me that this might have been an accident. For example, the firm might have been handling their paid search in-house and then subsequently decided to outsource to an agency and forgot to turn off their in house campaign.
I think that's a fair possibility in this case. However, I've seen several other instances where an advertiser is working with multiple agencies. In those cases, the "accident" card isn't as easy to play.