Marissa Mayer

Verizon's acquisition of Yahoo's core Internet operating business for $4.8 billion marks the end of an era—and perhaps the start of two new ones.

Yahoo, born in 1994, was likely the only successful example of the Internet's earliest business model: invest in "eyeballs," then magically monetize page views to generate profits. Much to the chagrin of a generation of early Internet investors, there was no magic—there was only the old newspaper model of basing ad prices on circulation numbers. Though Google and Facebook are now the dominant examples of ad-driven eyeball monetization—accounting for roughly half of all Internet advertising revenues—Yahoo! was its first true beneficiary.