Jason Cohen from A Smart Bear:
Ignoring most of your potential market, how are expert, power-users doing this today, without your software?
Jason suggests focusing on the power-users first, because they're the go-to guys for the industry. Solve their problems, in their terms, and market it directly to them. Then, later, expand the scope of your marketing as your user base shifts.
This is in contrast with the typical fly under the competition strategy many people follow, but Jason makes a good case for why this works, in both a consumer and a b2b context. The article is long, but worth your time.