Background: I've been working on building my first web application for a couple months or so. One-man show. I'm also learning Ruby on Rails - at the same time. I figure it's good practice to have an actual product to work on while I'm learning the language/framework, especially because this web app is one of the driving factors behind my desire to learn how to program. On top of that, I've got some decent design chops and I've put together what I consider to be a beautiful landing page (with signup, headline, brief desc, etc) as well as a basic user interface page.
As long as school doesn't throw my schedule off, I'm shooting to have a very respectable (beta) product launched by Jan 1, 2011 with all core features. I won't release with every single feature I've ever imagined - big fan of the "release early, release often" mantra. Other features will be pumped out after release. Freemium business model.
Question: Do I release a "teaser" page right now requesting emails from potential users, or do I just wait for the initial launch? The teaser page would be designed in the likeness of the actual web app with header, info, product description, etc but would have a field requesting emails instead of a signup button (is there an actual term for this type of page?). If I do decide on a teaser page prior to launching, how early is acceptable?
I see pros and cons of both approaches, and would love to hear your thoughts on the subject.