Alex Turnbull from Groove talked about how they get people who read their blogs to sign up for a free trial.
1.First, they get blog readers to sign up for emails by:
a) Free eBooks (conversion rate of 1% to 1.5%)
b) Kept the form at the top (1%)
c) Contests that give away [a bunch of books] (9.8%).
d) box that pops up as the reader gets close to the end of the post (1.4%).
2.Once they have your email address, they send you a number of emails with their best content.
3. After a few letters, they send a message that tells you about their paid service and invites you to try it. The exchange rate is 3.7%.
Source: www.groovehq.com