Microsoft & Lookout - What does this mean?

Microsoft announced today that they are acquiring Lookout, a small Silicon Valley software company that makes software to search through emails within Outlook. Am I the only one that really wonders what is going on over at Redmond? Isn't Outlook part of the Office suite that generates billions in revenue and profits? Isn't the company dumping millions into R&D around search? My final question is why would Microsoft need to go out and buy lookout given the resources they have and the fact that they should have more knowledge around Outlook than any other company in the world. Granted they might have bought the company on the cheap, but I just wonder if this is another case of the company wasting more shareholder money.