If you’re a lawyer, you likely have a profile on Avvo.com, even if you have never visited the site. Avvo.com, which bills itself as the largest online lawyer listing service in the world, has developed a database containing almost every lawyer in the country. Each gets rated from 1 to 10, with 10 being the best possible score. Clients and peers can post positive or negative comments.

"Why am I only a 6.5 out of 10?" A trial lawyer asked me a couple weeks ago. "And why does John [the lawyer across the hall] have a rating of 10?"

First things first: Why should you care?

If you’re a corporate, business-to-business attorney, you might not need to care very much. If you’re a business-to-consumer attorney, your score might matter a great deal. The clients you’re interested in don’t tend to hire lawyers very often. They don’t understand what makes a great or even competent attorney. They might turn to Google, where they’ll be bombarded with advertisements for lawyers. But they don’t want ads—they want unbiased information.

That’s where Avvo comes in. "We use a proprietary software that goes out and crawls the web to build an automated profile of these lawyers," said Mark Britton, Avvo’s founder and chief executive officer. "Some lawyers are saying, ‘I’ll do good work and clients will come to me.’ But the problem is, if you don’t have an online presence it is extremely difficult for people to evaluate you."

Avvo evaluates attorneys based on the information gathered by its webcrawler. "Avvo is replicating the process that someone sophisticated would go through in choosing a lawyer," Britton said. "Think about what you would do for a family member trying to find a lawyer in another state. You would work the web. You might check their license, do a Google search and check LinkedIn—maybe blogs or even Facebook. Avvo starts with the bar records and then goes from there."

Obviously, lawyers with strong web presences will score well. But Avvo also allows lawyers to supplement their profiles with information about any clerkships they served, the schools they attended and firms they have worked for. The technology-averse can even ship their resumes to Avvo, which will enter the information on their behalf. This added information could raise an attorney’s score.

If you have a common name—say, John Smith—"there is a much bigger need for adding in your own information, because the crawler has a hard time distinguishing," Britton said.

Lawyers are especially wary of Avvo’s comments feature—what if a competitor attacks them or disgruntled clients try to destroy their reputations?

For one thing, the service’s terms of use forbid personal attacks; any information posted must be predicated in fact. " ‘This lawyer sucks!’ would never be approved in our system," Britton said. "We also require contact information for everybody who makes reviews." Finally, Avvo scrutinizes every comment before posting it. Lawyers can challenge comments, and if a reviewer doesn’t respond, the comment comes down. If he or she stands by the comment, it stays up.

"There is a very real process to make sure it isn’t a competitor, and there is a place for the attorney to respond to the review," Britton said. "They can say, ‘I’m not sure this is a client.’ Or they can say, ‘I had no idea you felt this way—this isn’t the way we normally do business and we would love to make it right.’ "

There is also room for endorsements. "Having the right attorneys endorse you is valuable," Britton. "Lawyers in your own firm will not be very helpful. Opposing counsel in a case will be very helpful, but it is capped how much it will help. Clients actually don’t affect lawyer ratings at all. Non-lawyers have a hard time evaluating the quality of legal services, especially if it is a one-off. Clients often have unrealistic expectations."

One example Britton gave was a man accused of murder who was found guilty of manslaughter. His lawyer may have represented him very well indeed, but he might yet feel aggrieved.

It may be time to claim your profile. Avvo claims more than 5 million visitors per month and more than 125,000 participating lawyers. "It’s a win-win situation," Britton said. Clients, he said, want a third party to provide more unbiased information and lawyers want to provide information in a trustworthy way.

Adrian Dayton is an attorney and author of Social Media for Lawyers (Twitter Edition). His website is adriandayton.com.