I was setting up a 'Coming Soon page' for a client, with an email field for users to register for updates and links to the FB page and Twitter account of the Web app. Their concept isn't ground breaking, their USP is their tie-ups (which will probably be confirmed AFTER their soft launch).
The debate is about having FB Share and Tweet buttons. A user may want to signup, but not sure if they are likely to 'stamp their approval' by sharing it.
Not having those buttons will definitely reduce clutter on the page and make the 'email' the only call-to-action.
Is there any research on weather these social interactions are useful for a 'Coming Soon' page?