For Tony Bates, joining Skype was a “no brainer.”

By Dan Primack, senior editor

Skype CEO Tony Bates

FORTUNE — Every year, Tony Bates and his wife make a list of future goals. In 2007, Bates was a 40-year-old Cisco CSCO executive who wrote down that he wanted to become a CEO by the age of 45. He then listed four companies — all consumer-focused, despite his enterprise pedigree — that he hoped would offer him the job.

One of them was Skype, Bates said today during Fortune Brainstorm Tech in Aspen. So when Skype’s private equity owners came calling last October, it was a “no-brainer.”

“There are very few of these opportunities,” Bates said. “How many companies are there that really have over 100 million users per month and over 100 minutes of per user engagement per month? You can count them on one hand.”

Bates also expressed excitement about his upcoming opportunities within Microsoft MSFT , which recently agreed to buy Skype for $8.5 billion. Bates said he expects the deal to close in October, at which point Skype will become the first company ever acquired by Microsoft to be treated as its own division within the company. Bates will report directly to Microsoft CEO Steve Ballmer, although he declined to say how long he was legally committed to remaining with the software giant.

Read the full transcript here.

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