Thought provoking article by Fred Wilson on Mobile vs. Web App development. This is a really good article if you're into this kind of stuff.
A VC: Rethinking Mobile First:
"All in all, mobile service apps turn out to be a horrible place to close viral loops and win at the retention game. Only a handful of apps have succeeded mobile-first: Instagram, Tango, Shazam, maybe 2 or 3 others."