8. eGroups: $432 million
The 8th most expensive Yahoo acquisition is eGroups.
The email-list management website which allows users to create their own mailing lists and others to sign up for membership on the list.
The website provided archives of the messages as well as list management functionality.
And plus, each group also had a shared calendar, file space, group chat, and a simple database.
It was acquired by Yahoo! in August 2000 for about $432 million and became Yahoo! Groups since then.
