Use All Possible Channels - Regular Face to Face Meetings
When you refer a customer to a fellow member, what you are saying to that person is "I trust you with my customer/friend/family member, and know that you will do a good job for them". In order to be that confident, there really is no substitute for getting together, face to face on a regular basis and learning about each other's business.
Flexible times, familiar structure
Just because our favourite time of day for networking and referral gathering is over breakfast, doesn't mean that everyone is expected to get up at ohmygoodness o'clock. IN8 Networking chapters can meet at any time of day they wish, so an area can support a breakfast group, a lunchtime group and an evening group. Provided they have enough members that is. Enough is usually 20 or more per group, so it is not a challenge to find that many like minded business people in an area and encourage them to meet up at the same time each week in order to get more business.