Head on the internet, and feet on the ground, as Grillo himself puts it.
So what does this mean for the developer of software tools for the federal market? Presumably you have a Facebook page, or a Google Plus page, or at least a Twitter account. Wherever you have established your online presence, you have identified your community. So, when you have an event, invite your followers.
Realistically you can't hold a rally and have thousands of people cheering for your software tools, or web widgets. But you can generate a steady flow of traffic to your booth at the trade show and/or guarantee a full room when you present at a conference or the monthly meeting of a user group. For purposes of building a prosperous company, that is sufficient.