Here are some of the ways that I've experimented with:

1. A bi-monthly newsletter highlighting some specific features of your solution. The audience would be the end users.

2. Sharing a new release video with your end users.

3. Creating a custom video for your users talking about the overall benefits of using your solution.

4. Usage analysis to gauge end user adoption of your product. Identify the power users and encourage them to work with their un-adopting peers. Offer a small reward or recognition in return for helping you.

5. Offer quick training on specific features.

6. Engage with both the top level management, and the end users, all the time. Make sure you're all on the same page.

7. Keep an eye for growing the footprint, and any other competitor lurking in the background. Make friends with the end users who wouldn't hesitate to give you some of the internal details of conversations.