To understand why clients don't return calls, we first need to evaluate their situation. Busy decision makers don't want to be distracted by salespeople who may be putting their own interests first.
There is never enough time to establish a solid or productive new business relationship at most networking events. That is why you should invite any interesting new contact to meet you a few days later for a client lunch. If you want to increase sales, this is a critical step and the very best way to convert your efforts at networking into increased sales.