There is only one I believe in. Before Bomb and After Bomb are the timelines we'll be discussing, and here is how the earth started:  
 
Many years ago (3 give or take) the internet was kinda lame with video game reviews and stuff. Then a giant bomb exploded and a group of mighty duders initiated the best free thing on the internet (and in my opinion the best thing on the internet period).  
 
Then, 3 righteous years later, they gave you the option of paying for even more fun stuff! 
 
And now we wait to see what comes next.