Even if you manage to join several really good and relevant groups relating to the insurance industry, or even connect with other groups whose participants may need insurance, it is not the place to start selling your services and policies right off the bat. Do not post messages that sell your services. Who wants to be regarded as the pushy insurance sales person only there to sell stuff? Additionally, most groups forbid members selling in the group.
Instead of posting material that might get you on the wrong side of group members, post relevant content about the insurance industry, helpful tips or tactics to deal with claims, how to best help an elderly policyholder find what they need and so forth. Tell stories. Help others. Reply to questions citing your own experiences in selling insurance. All those methods of communicating are relevant and still get the message across that you are an expert in your field.
Sometimes less is more, even when it comes to marketing yourself, your agency, your expertise, services and products.