As the annual Quakecon event kicks off in Dallas, Texas, publisher Bethesda has made its debut MMO available via the popular Steam service for PC and Mac. For the duration of Quakecon (until July 22), the game is also enjoying a 50% off sale.
Unfortunately there doesn't appear to be any outlet for existing owners of The Elder Scrolls Online to convert to a native Steam version of the game. However, the Steam offering still reportedly uses the propriety launcher for downloading and patching anyway, so adding TESO to your Steam library as a "Non-Steam Game" already achieves a similar result anyway.
Head over to The Elder Scrolls Online's Steam page
to take advantage of the sale.