Secondly, you can send your customers a special invitation to attend. Every attendee will benefit from the knowledge shared and each should be able to apply it to his or her business. Encourage your customers to become involved in this series by asking them to sponsor one of the seminars in exchange for advertising their business at the beginning of the program and introducing the speaker. Sponsorship might also include a special display table in the room. It's important to charge a nominal admission fee to cover your costs.
People actually place a higher value on a program when there is a charge.
And you can always find local consultants who will welcome the opportunity to share their expertise in public since this is a great marketing opportunity for them. There are a myriad of possible activities you could sponsor and coordinate to get your customers together and allow them the opportunity to meet. For example, you could host a series of roundtable breakfasts. This should be an intimate group of 10-12 customers who share some of the same demographics. Perhaps the size of the company each of them owns is similar.