There are few CMOs in the telecom industry who can talk tech as well as David Christopher. As the chief marketing officer of AT&T Mobility (NYSE:T), Christopher oversees much more than just promotions and pricing. He also handles product strategy and execution for AT&T's wireless products as well as its entertainment products.

Christopher was instrumental in helping AT&T maintain growth despite its loss of its iPhone exclusivity in early 2011. He also was behind AT&T's introduction of shared data plans last summer.

Interestingly, Christopher also plays a key role with the company's developer community, and he is often front-and-center at AT&T's annual developer summit. His understanding of the developer ecosystem likely comes from his days as a product marketing executive with Palm before he joined AT&T.

One key message Christopher always emphasizes is that AT&T wants to be open with developers and easy to work with, a concept that most find surprising coming from a Tier 1 operator. But as Christopher notes, without openness, developers will likely take their innovation elsewhere. And big operators desperately need innovation to remain competitive.

Christopher and his colleagues at AT&T are particularly bullish on the company's latest innovation--the Call Management API. Currently in alpha testing, the Call Management API will let customers take their existing AT&T mobile phone number with them regardless of what device they are using. The company envisions this offering as a way to circumvent the over-the-top players that are currently taking voice business away from the big operators.

Look for Christopher to continue to be a key player at AT&T, particularly as he and his team navigate new products from BlackBerry (NASDAQ:BBRY) and Windows Phone licensees and stem competition from upstarts like T-Mobile USA and others.