Dear google expert staff,

I plan to soon open my own fast casual restaurant, projecting $15.00
average check, and ideally turning tables 30-40 minutes. Debating
whether to serve alcohol or not, I know it will increase my average
check, but it will also result in less table turns. If deciding to
serve beer and wine, how much will my average check increase? and how
much of the bottom line will serving Beer and Wine contribute to?

This might be of help to you.
http://answers.google.com/answers/threadview?id=548176

Difficult to answer the question with out additional information.

Are 'all' of your tables filled everyday for your busy periods (i.e.
lunch/dinner).  If not, I can't see how longer table turns could harm.
 If this is the case, I see only upside potential.  If yes, the
variable and unanswered question is "How much will serving alchohol
decrease your table turns by?"  If you can answer that, the match
should be pretty easy, given you have an estimated amount your average
check would increase by (with alchohol).