User engagement wish list

[emailapphost]

Here are some user engagement ideas I would like to see from my experience.
I am unable to make this a request for paid services myself, I am more hoping that someone will get ideas for plugin that can do some of this. Please do let me know.

I see that I am losing 90%+ of new forum sign ups after the first initial sing up and look around, they never return.
They never get engaged in the conversations and leave.

I would assume the way to get new users engaged is to send them a number of emails and links through (Facebook, YouTube, Twitter, RSS etc etc) to pull them into the forum they have singed up for.

- More welcome emails after 2 days, 1 week, 4 weeks etc.
Ability to set this up in the admin section.

- Secondary email, and ability to send all email to one or both stated email accounts.
Most people have more than one email account now days.

- Ability to have part of thread or post text in welcome emails.
So that user will see and be reminded of his own post.

- Ability to send email after 1 week with "Top 5 conversations in your forum X".

- Ways to automatically sort users after what forum they have engaged in, looked at, posted in. So I do not send follow up emails to those interested in oranges to those interested in pears.

- Way to give users an incentive to sign up. A lottery for a free iPod, a discount coupon or something other strong incentive.

- Monetize the actual singup information by ethically sharing it with others, I am working on a plugin for this that will be launched before long, some of you might find it useful.
The revenue can be directed into a incentive to sign up.

- "Send this thread or post link to a friend" in the forum interface a button
where you can send a post or thread link to a friend by email to engage your friends
in your forum engagements.

- Invite my friends in sign up, write their email addresses when you sign up and an invitation email "from you" is sent to your friends.

- Pay to make sticky. Pay USD 10 to make your post sticky.

- Signup tracking code, so I can see where my sign ups came from.
Unique id link or tracking script.

- "Introduction to new users" videos, on YouTube. How do you use vBulletin?
And a way to allow new users to watch this video as they sign up.

- A way to automatically engage users that are on YouTube,. Facebook, Twitter etc in the singup process.
What about a way to automatically join Twitter feeds, Facebook groups etc in the actual vBulletin signup?