An anonymous reader writes "Microsoft's $240 million investment is much smaller than the rumored $750 million that Facebook sought. Why the difference? Wired Epicenter's Terrence Russell analyzes the deal, and points out three good reasons why Microsoft got a 'bargain'. 'Microsoft Only Needs an Entrenched Position - Ballmer's plan to acquire 100 startups in 5 years is still sketchy, but we got the point -- Microsoft wants momentum. If the company is to go forward as planned then taking a small, strategic piece of Facebook makes sense. Microsoft's financial interests in Facebook's ad platform already exist, so it only makes sense to strengthen that tie as the hype builds.'"