This afternoon at ILM East, At&t’s Maria Kermath outlined the do’s and don’t’s of approaching and navigating the sales cycle of AT&T Interactive. As bus dev lead for AT&T’s “product factory” she straddles partner vetting and product development.

This is important given the level of interest among start-ups to quickly scale on the back of a digital media giant. AT&T has 30 million monthly uniques across properties (12M in mobile), 1 million advertisers, thousands of sales reps and $1 billion in revenues. It’s also Google’s largest AdWords reseller.

Kermath has an affinity for the IP offered by small and nimble start-ups. But due to volume of incoming requests (about half the companies she vets), brevity is vital. You need to be able to pitch her in under 5 minutes. If interested, the next step is a 20-minute call, followed by an hour with a product manager.

“It is like pitching a movie,” she said.

“We have a couple hundred engineers, and you need to empower me to act as an ‘evangelist’ on your behalf. That’s where the story is really important.”

Another important attribute is patience, given long sales cycles. Start-ups should be ready to pitch their product 10 to 20 times in 12 months. They should also go in with appreciation for the strengths of a longstanding traditional media company like AT&T, rather than shrugging it off as old school.

A recent start-up scoffed at her team’s recommendation to include fax contact information for a lead gen product. Here the “Silicon Valley effect,” as it’s known, is rampant among engineers who assume everyone can just pick up an iPhone and connect as easily as they do.

Of course, the same doesn’t apply to the long tail of rural America where AT&T has deep penetration — not to mention the very scale that attracts start-ups to its door. So start-ups should go in with the realities of rural SMB and user behavior in mind — and to trust AT&T with what it does best.

“You may know algorithms and machine learning and recommendations engines,” she said, “but we know advertisers and have been working with them for over 100 years.”