It isn’t easy to come up with new hot-selling products every now and then. It's as hard as creating a new and foreign color! At the same time, you just can't be selling the same old products in the Internet market for a long run and the reason is because the market is always looking for something big and new.
If you persist, the value of your out-dated products will decrease and eventually, they won’t sell for you anymore.
Otherwise, you will be cracking your head for new ideas to create a product because without a product --- You will have nothing else to sell and your income stops there.
You don't want that to happen, do you?