Google Analytics recently introduced Smart Goals.
Smart Goals are goals that Google themselves configure within your Analytics account to measure the activity of your best visitors. This is based on visitor behaviours such as the time they have spent on the site, the number of pages they have visited and an undoubtedly bewildering array of other signals that Google have doubtless determined to indicate desirable behaviour from their analysis of user data.
And, let's face it, Google have more data than... well, than anyone.
So these goals will be the best we can get, right? Nope. Not even close.