Ultimately, the decision about how to run your business and whom to sell to, is yours.
If I were in your position, I'd consider a couple of things...
1) IF you were to sell to service companies and/or etailers, and your Brick and Mortars caught wind of it, would they dump you? If they did dump you, would the net loss of them as clients be offset by the purchases of those etailers and service companies? If the answer to that is no, then I'd probably opt not to sell to the etailers and service companies. IMO one good brick and mortar customer can order more in one week than many service companies will order in a month... depending on the size of the company.
2) Could it be that some of *your* customers, *are* your customers now and not customers of the "LA Wholesaler" because LA sells to the service companies and etailers, and you don't? Perhaps not the only deciding factor, quality and price have to speak for themselves also, of course, but for those of us who also look at the bigger picture, it's a consideration.
Business is business... but the bottom line is whether you will gain more than you stand to lose based on your decision.
HTH
Jenn