Sales & Marketing is quite a b*tch and most of the (geeky)startups actually face hurdles in cracking this piece.

More so because geeks inherently have very little respect for sales professionals and importantly, lack of understanding of the entire process (and behavioral aspects).

Sales Funnel
Sales Funnel

Here is a great presentation by David Skok, GP at Matrix Partners detailing the entire Sales&Marketing process very beautifully. A must view.