Microsoft and Facebook ad to the resurgence of the next internet bubble.

This week’s 1.5 percent share acquisition of Facebook by Microsoft for a valuation of $15 billion represents more than just the biggest deal of the year. And while it’s not the largest investment made, it’s the biggest indication of what a company is willing to pay for a start-up like Facebook with the fastest-growing social media audience, even though there is no clear monetization strategy in place.