SMB is a tough market, I've been working in for the past 4 years, on my startup BizeeBee.
However, you seem to have a really great focus: managing subscription based services.
Depending on the size of the SMB (more medium) there maybe one person managing the services, such as a business partner, accountant, or CFO. However, if it's a smaller business then it could be one person who is wearing multiple hats, and then it's a matter of convincing them to give you the time of day.
You might want to offer a little bit more a teaser, by addressing some of the problems SMBs experience when managing subscription based services, asking if the SMB you are talking to experiences it, and who the best person would be to talk to regarding the management of services.