PORTLAND, Ore.—You could say Urban Airship is really taking off. Launched in June of 2009, the company has sent 2.6 billion push notifications across iOS, Android and BlackBerry. It's authenticated and delivered more than 2.8 million purchases via in-app purchasing, and it boasts companies like ESPN, Warner Bros., Tapulous and Dictionary.com among its customers.

It's come a long way since CEO Scott Kveton more or less introduced the company to the world at Apple's Worldwide Developers Conference at Moscone Center in San Francisco in 2009. Because he didn't have a ticket to actually get into the event, his strategy back then involved going to Costco, buying up a bunch of pastries and handing out goodies outside the venue. It just so happened, Urban Airship was offering services specifically for iOS developers, all designed to help them make money. It was a captive audience as attendees lined up before the doors opened.

This week, the company rolled out a similar set of services for the Android developer community. As you might expect, Urban Airship expects its 2.8 million in-app transaction figure to grow even faster. The company has been participating in Google's beta program and developing in lockstep with Google to bring its tools to market. Last week, Google said it was enabling the in-app billing feature for Android.

In what has been described as a "last mile" type of service for the apps world, Urban Airship provides push notification, rich messaging, in-app purchases and data tracking on a cross-platform basis.

Based on a quick tour of Urban Airship's headquarters in Portland's Pearl District on a recent Tuesday afternoon, it's clear there's a lot going on. A glance at the multiple walls of white boards reveal all kinds of formulas and brainstorming sessions. Kveton says the white boards were a lucky inheritance from the former tenant – product design consultancy Ziba – and are a key part of motivating the creative processing that goes on there.

In-app purchasing requires significant server infrastructure, as well as technical know-how. Part of what Urban Airship offers is the ability to figure out the best time to deliver content and deliver it then. Sports news is an example of the type of notifications that consumers will want on a frequent basis, but that's obviously not the case for all apps. The company also provides a security component, validating purchase receipts before delivering content to the application, and it tracks updates to purchasable content and notifies users when updates are available. The company says it allows developers to fix bugs in their updates without shipping an additional update.

Kveton notes the "freemium" model, where apps are free for initial download and users pay for additional content, represents a fast-growing area. Research firm Distimo says 34 percent of the revenue generated by the most successful iPhone apps in the United States was generated by free applications featuring in-app purchases. The share of revenue generated by in-app purchase more than doubled in the six months ending in December 2010.

Urban Airship recently introduced Embedded Push, an alternate push notification system for Android to Google's own C2DM. Embedded Push is more robust than C2DM and works on versions of Android from 1.6 and newer; C2DM works only on devices running Android 2.2 (Froyo) and newer and requires the installation of the Android Market and a Google account on the device, adding more requirements for developers.