Firstly, congratulations on running such a successful business!

There is no silver bullet here. Back to basics. Sales = understanding your customer's needs and then meeting/exceeding them. If you are targeting independent stores, they will all have different needs, based on their existing strategy and constraints.

In my humble opinion, you have the option to either look for a communication channel that can reach a broad spectrum of independent store owners, or pound the pavement and try to create deep relationships with a smaller number of high potential clients.

The strategy will depend on your available resources, and whether you are looking to build new sales channels for independent products, or your entire line. Otherwise, a lower margin alternative may be to sell through a distributor to gain volume.