Don’t force me to register as a community member to download your free report/ebook.
That’s backwards thinking. It's far better to include a link at the end of your free report where I can discuss the findings and implications. Highlight specifics debates I can join right now relating to what I have just read.
Now try to spread that report like wildfire. You want as many people using this as possible. Add a “Twitter This” script at the end of your report that lets me post the link and a short message directly to my Twitter followers about your ebook. Why not also add a box showing the latest tweets about your #ebook?
It's an instant community.