I think Verizon would buy Yahoo so they could further monetize their subscriber base.
Buy Yahoo.com, make Yahoo.com the default home page of every customer.
They do this in other ways - I'm a FIOS customer and I don't use their DNS because you will see ads anytime you mis-type a domain name. You can turn this off with their not-so-simple instructions that any Baby Boomer will be completely unable to do:
Why Verizon would buy a site like Yahoo is still a mystery to me, but they own a lot of other junk as well.