(Disclaimer: I'm partial to "Mega Drive" myself.)
Wikipedia has this
https://en.wikipedia.org/wiki/File:Mega_Drive_vs_Genesis.gif
blue = Mega Drive, red = Genesis
Linked here:
https://en.wikipedia.org/wiki/Wikipedia_talk:WikiProject_Vid...
(didn't find the sales numbers, for those wondering. Sorry!)
Love that chart! It could also apply almost exactly to the "Buster Bros." artocle (everybody else other than North America knows it as "Pang"). This sort of rewriting of history is rife on Wikipedia.
I guess parent is pedantic about Megadrive instead of Mega Drive