Dead as a dodo

From: http://www.bbc.co.uk/worldservice/learningenglish/language/2013/02/130207_todays_phrase_dodo.shtml

A dodo

Dodos became extinct in the 1600s. Photo: Peter Macdiarmid/ Getty Images

Today's Phrase

If something is 'as dead as a dodo', it is no longer important or popular. This phrase is often used to talk about ideas or trends.
Examples
In the past people used to watch and record videos on VHS, but now that format is as dead as a dodo.
The idea that smoking is good for your health is now as dead as a dodo.

Take note

A 'dead duck' is something that is not successful.
Frank's coffee shop business was a dead duck sadly. His coffee was just awful, and the shop was in a bad location.

Interesting fact

The flightless dodo was first discovered on the Indian Ocean island of Mauritius in the late 16th Century. Within a few decades they were extinct. Before the arrival of man, the dodo is thought to have evolved to such a large size because it had no natural predators and plentiful food.