Following the news that Blizzard has banned "several thousand" Hearthstone bot accounts comes a more severe penalty for players engaging in the process known as 'win trading'. Win trading, as I understand it, is when players game the system in Ranked Play by having two accounts battle each other, in order to artificially move themselves up in the MMR (MatchMaking Rating) rankings. While botters were initially given a two-month ban (the penalty has since been upgraded to a permaban from here on out), win traders have seen their accounts banned permanently from the get-go, as explained in a statement by Blizzard here. Here's the relevant part:
A few 'top' players have found themselves banned for win trading, including Specialist and Gabe Walls, the former of whom found the flaw in Hearthstone's new ranking system and wrote about his taking advantage of it nearly a year ago.
What does having a high MMR get you? Nothing, at this point, although as BlizzPro put it, these bans could have made a big difference to the BlizzCon Qualifiers earlier in the year.