Nobody you know uses Yaho mail or yahoo messenger? I kind of find that unlikely, considering yahoo messenger is the largest instant messenger service(followed by msn). Yahoo search I believe, but they are more than search.
Actual upon further search, Alexa says the top two websites in english by number of hits are MSN and Yahoo,Google is third.
http://www.alexa.com/site/ds/top_sites?ts_mode=lang〈=en
Lots of people use Yahoo whether you know them or not.