The key to having a successful business is to attract customers cheaply and then quickly monetize those customers at a multiple of what they spent to acquire them.  At least according to David Skok from Matrix Partners (and investor in HubSpot) - that link is to an interview in the Wall Street Journal.

I agree.

Too often startups make their strategy too confusing and complicated.  This is because they don't have the answer yet.  Most really successful businesses have a pretty simple model at the core.  Google, Ebay, Salesforce.com.  See?