David Bittiner has written a good piece about why lawyers should create content.
One thing that should perhaps be added to the discussion is how a well run content marketing strategy can help with physical word of mouth recommendations. How it can help people recall your name and company at the critical moment.
With many lawyers their interactions with clients may be at unusual but very important times in their lives (how often do most people file a patent, get divorced or sell a company?). It's likely that they'll remember the lead characters in these events but not necessarily all the characters nor in the vivid detail that you'd hope. More importantly, if your client contact was through a one-off meeting or a networking event, your profile is likely to go out of focus really quite quickly.
If a level of contact is maintained, however, particularly through a medium (like a newsletter) that is of value to the potential client and one that demonstrates your expertise, the chances of them remembering your services rises enormously.
The majority of your work should still be won by recommendation and word of mouth from new and existing clients. But remember that your value to your business is your knowledge and expertise. Of course you are not going to give that away for free, but consider how you engage with your target client pool or industry sector. Wouldn’t some of those in your target groups want to know of your continuing expertise in your chosen field or sector? Wouldn’t a journalist in your field want to talk to you about your expertise and broadcast that knowledge?