I would try reaching out in various channels (like Linkedin mentioned above, Twitter or even scouring some meetup groups that might attract the person that might fit the expertise you are looking for) and presenting the value proposition.

Equally, If they have the right alignment ( background experience that speaks to the software business you have-- like experience with SaaS or PaaS or cloud based software companies as a mere example) you could ask them to do some "trial" work to see if it is a good fit (on say a 30-60 period). Most Marketing and Business Development folks are looking for interesting opportunities to solve problems and companies that have good growth potential (this doesn't mean growth to exit like you mentioned, but areas where they can see the business expand in logical ways that fit the business).

Good luck! Happy to help any further if needed.