Here’s what you can do: Write your own report deciphering the in’s and out’s of using that tool. Now when people search for help, your report is the one that they will see because people will be linking to you; the expert who helped them harness the power of that tool.
Any resource you can create that people turn to is something you can give away. Ask for an email address so you can send the download link and make your resource so good and comprehensive that others link to it and encourage their readers to go get it.
Your resource could be a definitive guide, a comprehensive study, a massive and continually updated survey, a collection of something, a massive swipe file or anything that is so terrific, people tell other people about it and link to it.
I’m not saying it’s necessarily going to be easy to create this resource, but you can always outsource some or all of the creation. The key is to make it so terrific; it dominates its field and people would gladly pay serious money for the information it contains.
Place something like this on your website for free and you will automatically get good backlinks and your email list will grow without effort. Be sure to keep it updated, too, so that it continues to draw traffic for a long time to come.