The best way to gain a hold into a market that already has many players is to make all products available easily under yours and add some values your competitor

The best way to gain a hold into a market that already has many players is to make all products available easily under yours and add some values your competitors can't provide (convenience, simplicity, single-point of access and purchase). Some people are willing to pay a bit more for that, and once you grow big enough, you can put pressure on the content providers to accomodate more of your requests. And you could also start being a content provider yourself and add some exclusives to your established userbase to retain them.