GeoCities
Yahoo -> shutdown (2009)
Massive user page deletion.
Acquisition Graveyard
A murder-board of beloved services consumed by bigger platforms.
Delicious
Yahoo -> AVOS -> multiple resales
Identity diluted after ownership churn.
Tumblr
Yahoo -> Verizon -> Automattic
Policy changes and strategic drift.
MySpace
News Corp -> Specific Media -> Time Inc
Social dominance never recovered.
Vine
Twitter -> shutdown
Cultural giant, product sunset.
Jaiku
Google -> open sourced -> discontinued
Early microblogging trailblazer.