As a lighthearted show that appeals more to young, female viewers, Supergirl does seem better suited to the CW than its original home at CBS, which tends to skew toward an older demographic. However, CBS Corp. CEO Leslie Moonves says that the show was never really in danger.
Speaking to Deadline, Moonves admitted that Supergirl "fits better at the CW," adding that, if it hadn't picked up the show for its second season, CBS probably would have taken it back anyway.
Since the CW is owned by CBS, this should be a smooth transition. Plus, this opens up new opportunities for Supergirl to cross over with other DC Comics shows like Arrow, The Flash and Legends of Tomorrow, which also air on the CW and are all produced by Greg Berlanti.
When asked about the possibility of an Arrow/Supergirl crossover, Arrow star Stephen Amell said, "Do bears you-know-what in the woods? I think that it’s highly likely that if you have four DC superhero properties on one network, that is an opportunity that may not exist again and certainly hasn’t ever existed in the history of television. I would expect that we would do something."
So, Supergirl's move to the CW isn't just good news for Supergirl fans; it's good news for fans of DC shows in general.
H/T The Mary Sue