How to launch a new feature on your site

Hey all. I am building a new feature on my site that will be an opt-in for some users. I am curious to hear of any good patterns people have used for this sort of thing. My approach thus far has been:

  1. announcement on user dashboard of new feature
  2. link to a form for to be registered as a prospective user (some additional data would need to be collected from the user)
  3. admin gets an email and visits a page to confirm or request further information
  4. user then has access to the feature

Ultimately all the additional attributes for this feature will live in a hstore column on Users table - which is already there.

Any tips much appreciated!