Dropbox offered its customers a 150
megabyte storage bonus if they linked their
Dropbox account to their Facebook or Twitter
account. They also created a refer a friend
campaign that would give users 500
megabytes of free storage for each friend they
Spotify drove it's rapid growth by integrating
the software with Facebook. Instagram
followed the same approach.
Twitter noticed that it's users were signing up, but
then abandoning the app. Using analytics they
discovered that people were far more likely to use
their account when they followed 5-10 accounts
on the first day. They build a suggestion engine
that would prompt new users to immediately
follow new users that pertained to their interests.
This greatly increased retention.
Mint used it's blog to build landing pages on
nearly every personal finance question,
effectively targeting it's ideal market directly.
Apple and Blackberry turned their devices into
advertising engines by adding "Sent from my
iPhone" and "Sent from my Blackberry" to
every message sent.
Reddit created hundreds of fake user profiles
in it's early days to generate buzz.
Pinterest launched as a invite-only service that
was exclusive, driving up demand and building
interest and industry speculation.
Gmail launched as an invite-only service as
well (before Pinterest did of course)