Sharing Versus Selling
Sharing your knowledge and expertise is not the same as selling your services. While the eventual expert status can help you secure more clients the process shouldn't be about advertisements. It's acceptable to inform people of your practice and provide details such as office hours but it shouldn't go much further beyond that.
Additionally, any information you offer needs to be genuinely useful to the people you're sharing it with as opposed to pleas to be hired or to have them contact you directly at every turn.
For example, if you're a divorce lawyer and offering insight into the different types of spousal support that may be ordered in your area you need to actually share that information within the context of the work as opposed to asking for phone calls to your office in order to find out the answers. By being willing to share what you know upfront without any guarantees of payment, future work or recommendations you showcase that you're truly knowledgeable and helpful and not just looking to make a quick buck.