Bill Gurley surmised 10 properties of good quality revenue but since his post is a) very long and b) focussed on exit valuation multiples, here are the 7 that matter to me:
- Sustainable - good quality moats making it hard for the competition 
- Network effects - each new customer adds value to others, meaning viral referral patterns 
- Predictability - subscriptions being one of the best examples 
- Customer lock-in - it’s hard and/or expensive to move to a competitor 
- Gross margin levels - i.e. each dollar sold generates significant +ve cashflow 
- No customer dependency - i.e. no customer contributing more than 10% rev 
- No partner dependency - your company’s destiny is not tied to another’s management team 
I use this to rate the health of revenue regardless of exit plans.

