This isn't super complicated - Good Old Games and Steam have been having massive sales on games published by Deep Silver, which includes the Saints Row franchise. While the sales themselves offer some really great prices, the real steal is that one of the core entries in the series can be downloaded for free. Gamers can get their digital hands on a copy of Saints Row 2 for from either service at the low price of $0. Both versions are essentially the same, though the GOG version comes without any restrictive DRM.
The offer from Steam lasts until tomorrow at noon while the GOG offer only extends until the early hours of tomorrow morning.