Our experience with building products in the web 2.0, collaboration space has shown us a few things about bringing it all up to the welcome mat of the app - the home or the landing page.  I thought the subject is extremely useful for those who design and for those who invest in them.

Once you have an eyeball, what really prompts them to action?  A few of our observations, though I am sure, not all are relevant in each and every context.

1.   Get the users to submit thier interest in your concept.  It's easy and many of them do it if you ask them to.  In case you already havn't, see how Groupon does it.

2.   A 300 word statement of what the app is all about with an action button to Learn More or Sign Up.  See how Skype does it.

3.   Have multiple calls to action where it makes sense.   It's like offering multiple doors to the users.  They all lead to the same room (read similar end page/ functionality).   Cause different users are captived by different calls to action depending on their own personal context.

Let me actually draw you to a fantastic site that has some great articles and examples.  Seeing is believing.

Calls to Action help Users

10 Techniques for an effective call to action

Source:       Great Job folks.