It does seem to have taken a little bit of a back seat in the eyes of most startup founders, I guess it's not sexy like Facebook boosted posts or Tapjoy incentivized installs... but it's one that still works exceptionally well.

Moreover, of the startups I've invested in this year, 2 of the 5 that are making profits do it through an email list they curated from app installs and then sell access to that list to other companies who want to reach the customers they have.