earn its keep
To be valuable enough to be worth keeping. This device can be used in so many ways that it's really earned its keep in my kitchen.
earn its keep
If something earns its keep, it is worth the amount of money that it costs or the space that it takes up. In Bob's garden everything must earn its keep, with fruits and vegetables given priority over flowers. If you're short of storage space in your kitchen, whatever appliances you do have really need to earn their keep.