I see so many consumer startups brag about vanity metrics. If you're a consumer startup doing something that's not mobile-focused, the # of unique visitors you're getting per month as viewed in Quantcast or Compete just tells the complete story. And even if you're mobile-focused too because Foursquare actually gets over a million uniques through their website. No excuses for you not to as well.
That is silly and reminiscent of the late 20th century were it was all about eyeballs. I would even argue that number of visitors is actually a vanity metric (by your term) because it assumes that all visitors are equal (they are not) and that the more visitors the better (also not true, if the new users are less likely to stick around and use your service and become payed members).
