In 1977 New York was a city struggling with a number of social and economic challenges. A campaign to increase tourism was launched, one element of which was the ‘I heart New York’ logo’. Designed by graphic designer Milton Glaser (who incidentally did not charge for the idea), the ‘heart’ logo has long outlived the original campaign.
(I know all this because BBC Radio 4 recently broadcast a 30-minute programme about Milton Glaser and this iconic image).
‘Heart’ is now used widely as a verb meaning ‘love’ and has been recognised in the latest Oxford English Dictionary online update. Also included are popular new ‘initialisations’ including LOL and OMG.