We do inbound content marketing for Close.io and have grown our bootstrapped and profitable business using inbound leads only. We're targeting SMBs and tech startups on the web using our blog.

We produce 2-3 blog posts a week, 2-3 videos a week, 1 interview/podcast a month with a high profile individual. We promote our content on Hacker News, Facebook, LinkedIn, and Twitter. Recently we launched a book as well which we are promoting on all of the above avenues as well as on Amazon.

Here are the metrics we track:

1) Unique visits to close.io as a whole and on a per blog basis
2) Trial Signups
3) The conversion between 1 and 2
4) Comments/responses to blog post content
5) Shares on twitter, Facebook and LinkedIn
6) Up-votes and comments on HackerNews
7) Shares / Views on youtube.

Using the above we can usually pinpoint which pieces of content are most effective in bringing in the most trial signups. We can then fine tune our content to increate signups and eventually conversion to customers.

Let me know if you want to learn more about our inbound flow.