attempts, failures and retries
"Someone else did this before and failed." is a horrible feedback to give to an entrepreneur.
An entrepreneur does not build products for the sake of building products. He is out there to solve a problem. The first iteration of the product is a hypothetical solution to this problem. After the first iteration is launched, if the entrepreneur is flexible and capable enough, the product goes through an evolutionary product-market-fit process. Only upon the completion of this process can the product be equated with the problem itself.
In other words, past failed attempts to solve a problem does not mean that the problem is no longer there or that the problem does not have a viable solution. (e.g. The failures could be due to wide-off-the-mark first iterations or mismanaged product-market-fit processes.)