If you have a landing page set up where there is a specific call to action, watch a video or try out a service etc..
Try setting up a password protected post on your blog for that page, here you can ask them a few specific questions and get them to leave a comment.
You can also make yourself more readily available by leaving your contact information.
Once the prospect opts in to your landing page, you send them a card with the URL and the password to that post.
This can be a great way to break the ice with a new prospect.
This is just one way to use postal mail to build your online community.
