One of the reasons lawyers are slow to adopt web marketing is they are afraid of running afoul of state ethics committees by providing legal advice. Different people have different perspectives on this, and every state’s rules are different. But if writing articles for magazines or books is not legal advice, then it is hard to see why an online blog would be any different.
The key is that blog posts (like books) do not apply the law to any reader’s particular situation. As an author you have no way to know your reader’s circumstances. Your blogs simply offer an opinion on “the way it is.”
Where you could get in to trouble is in the comments. If you find your readers asking you specific questions in the comments it is probably better to invite them to schedule a consultation than to respond where the world can see. This protects confidentiality and your ethical obligations as an attorney. If you still feel uncomfortable, or if your state ethics rules are more stringent, you can always disable comments and simply suggest that readers call for more information.
Some lawyers also choose to build in disclaimers on their blogs. Writing a footer that says the information provided is for educational purposes only and does not constitute legal advice, can give you further security about ethical questions.
But just because local ethics standards exist doesn’t mean you should avoid content marketing altogether. Your potential clients are looking for a reason to like you. An informational blog shows that you are knowledgeable, generous, and can communicate with your audience.