You actually have millions of different options.
I like the social media strategies that others have suggested here. However, that depends on whether you have the time to actually carry them out. A successful social media strategy depends on three things: CONTENT, CONTENT, CONTENT. And it can be very tricky and very time consuming. You wanna position yourself as someone who provides valuable content to your viewers, not just someone who is desperately trying to sell something. But before you do that, you will need to profile your "buyer personas", i.e., who is your target clients and what are the problem that you solve.
Said that, and if you are serious about a solid social media marketing campaign, I'll recommend the following:
- If you have the time to do it yourself, find the bloggers and other influencers such as journalists who cover and analyze your industry. Leave comments in their blogs first, see what they write, and then launch your own blog. You may even wanna upload some videos of yourself.
- If you don't have the time, then hire a social media marketing expert or company to do it for you. I don't know how much it will cost, but I am sure it will be your best investment.
For more information about social media and its marketing potential, you can check out the bestseller "The New Rules of Marketing and PR".
Finally, and quoting Donald Draper from Mad Men, remember that success is related to standing out from the crowd, not fitting in. You wanna be the needle in the haystack, not the haystack. In other words, Why don't you give away your product for free? You will not make any money, but if your product is good, you will earn a REPUTATION. You will automatically become an expert in the arena of "add ons for sharepoint". Think about it.