That was an unexpected announcement this morning. They're going from 70% to 80% from Sept. 1 through Nov. 30. So that would be exactly the length of a stint with KDP Select.
If a writer was thinking about going to Select or Kobo for those 3 months, that could be a deciding factor. It's not the still measly 5 free days Amazon offers. You can be free for as long as you like at Kobo.
It's true that Amazon is the big boy on the block and IF (repeat IF IF IF) you expect substantial sales due to your involvement with Select, then you'll want to stay with Amazon. If you haven't seen great or have seen diminishing results with Select and their freebies, you might want to try Kobo.
This is an interesting move by Kobo, putting them into competition with Amazon. They are still a small player but obviously they don't intend to stay small (who knows what BN intends). Amazon needs this. I hope they respond with some kind of upgrade to author services because I have no interest in Select at all. It does nothing for me except tie up books that might sell somewhere else.
The key, of course, is discoverability. The site which makes it easiest for the work of writers to be found is where the writers will go. This is not a hobby, this is a business. It's about sales, it's about money.
Up until now these sites thought they were doing us a favor. That attitude seems familiar to me, where did I hear it before. Let me think. Oh yeah. Traditional publishing. It didn't work out so well for them and to continue to treat writers as though they should be grateful to have a place to sell their books will not work much longer for digital either. We should be grateful for each other. That's how this system will work best.