This is hilarious and nostalgic. ICQ has no place on this chart, you're right. And where is friendster? Where is classmates? I used to love Myspace as well. Ah, the day of "top friends" arguments... I still have a profile there with 30,000 fans of likely abandoned pages. One thing is for sure, we all should have learned the lesson of not depending on social media to be our "lists" (we still do this, and don't change— e.g. Facebook.)
And what is this mapping anyway? Activity per user? User growth rate?
Thanks for posting. This is was a big flashback. :)