Week 2

    Has become obsolete:

Before online streaming people bought DVDs. This also applies to music. CD's was invented in 1979, DVD was invented in 1995.

Then in 2001 Apple came out and presented iTunes. People could buy songs online individually instead of buying whole CDs. Almost the same happened with DVD/Blue-Ray. Platforms like Netflix, HBO and Hulu had ~1231% of sales income. So, since 2008 DVD sales have declined more than on 80%.
Personally I've never bought CDs with music or films. Online streaming platforms have taken over this niche.

    Survives to this day:

Ray Tomplison invented email in 1971 by creating ARPANET's network mail. He developed Username@nameOfComputer format. And by the 1976 3/4 of all traffic was emails.

Everyone is aware of email spam, but when did it started? Spam can be charted back almost to the start of Arpanet, but in early 90s it became a conspicuous issue. 

To sum up, email is 51 years old technology but it became as necessary as phone number.