This blog began as a much-needed distraction for me while I found myself in a hospital waiting room two and a half years ago, but it has evolved into the single biggest driver of information and insight I get about the mobile industry. Before I start writing, I spend a lot of time reading and thinking about the companies that make this business go, the decisions they make, what works and what does not.

As a result of the homework this blog has required of me, I’ve realized a few things about the mobile economy.

1. While consumers spend more of their smartphone time using apps, they tend to use only about 20 apps on a regular basis.

2. This means getting customers to download and use new apps can be really hard.

3. Consumers spend most of their app time using social media or playing games.

4. Banner ads, probably because of their small size on smartphone screens, struggle to get noticed.

5. The industry therefore has needed to invent new advertising formats built with smartphones in mind so that developers, brands and agencies have better alternatives to driving consumer engagement than banners.

6. Native advertising, especially on social media networks such as Facebook and Twitter, increasingly looks like the format that works best on smartphones.

7. As big as mobile advertising is and will continue to be, the mobile economy’s most powerful source of growth will come from mobile commerce – buying stuff on our phones.

8. Building a successful mobile enterprise is really hard, but achieving it is exhilarating (at least for me).

I’ve written a lot about each one of these things. At some point during the last several months, though, it dawned on me that I wanted to do more than just write about this stuff. I wanted to make it my day job, too.

That’s why I’ve decided to leave Microsoft and join Ampush, where I’ll head the company’s marketing team out of its New York City office.

Ampush is a leader in mobile-first, performance-based, in-feed social media marketing, which the company does on behalf of variety of different clients, from mobile gaming publishers to e-commerce companies. If you’ve ever used Facebook or Twitter on your phone and seen an ad in your news feed, then you’re familiar with the kind of work that has Ampush’s clients raving about the performance they see. Their ads work because they combine precise targeting and finely tuned creative relevance designed from the start to engage on a mobile device.

On top of that, as a Michigander I identify with Ampush’s Midwestern culture. The three founders hail from St. Louis, Chicago and Detroit. (You can read their story here.) Fittingly, their San Francisco conference rooms are adorned with sports memorabilia celebrating their hometown teams. I’m a big sports fan myself, so I’m pretty excited for the water cooler chatter.

This means saying “farewell” to Microsoft. Though my tenure there lasted only a year since the company completed its acquisition of Nokia, I submit there’s never been a better time to work there. Microsoft has a new fire in its belly, and I feel grateful and privileged to have been a part of its rejuvenation.

Now, though, I look forward to leading a wonderful team and telling the world about Ampush: how the company helps partners achieve great results (especially on mobile) and celebrating those wins like a game-winning touchdown, three-pointer, and home run, all wrapped into one.