There are several problems with dealer's only (especially internet/marketing only) meetings. First, there is such a wide range of structure and roles for "internet" people. You have BDC managers, marketing managers, social media managers, internet sales managers, group marketing directors, e-commerce directors, etc., etc. A person may fit one, a few, or several roles and responsibilities within the dealership. What is a hot or topic for one position doesn't fit into others.
Secondly and most important, this industry is so vendor heavy dealerships rely on vendors to do the work for them. As a majority, dealership personnel lacks a good understanding and can present on a topic. I've given several presentations in dealer's only meetings and when the discussion starts it's always "I have xyz do that for me.....". It's hard to discuss topics or action items if someone just gets a monthly report and/or a conference call once a month. Additionally, vendor talking points and sales often come into discussion. "I do this because xyz said it's do abc for our dealership."
