It sort of depends on the size of the businesses you are approaching.

If they are mom/pop stores or regional stores it should be relatively easy to approach owners/managers to give them the pitch. If it is a problem they have which they are aware of they are going to recognize how valuable your service is much quicker than a normal person would. If it is a multi-national company then it's more tricky to get to the right people and linked in can help you there.

I would figure out the perfect first company for your service and contact them. Focus on the first one to figure out what DSL you need to speak to talk to other people.