Let me first talk about the elephant in the room about finding Startup Ideas which generate extra ordinary returns.

YC assembles a Team of the Greatest Founders after extensive validation by the most qualified people in the planet to judge whether you have the qualities required to build a startup. (They may miss a good team, but the probability of them selecting a bad team is less than 10%)

YC mentors these teams ideas by making the best people in Silicon Valley available to these teams so that they can pivot and re-work on the most probable idea which may succeed

Expected Outcome to Founders: Conservatively 50% of YC funded Startups would be back to the point of their starting (Zero returns for the effort invested both for the founder as well as the investors) Some Founders may even have negative returns in Health, Relationship and sometime financially.

Extected Outcome to YC and the World in Large: Even less than 10% hit a home run, they have extra ordinary returns and the world becomes a better place hopefully because of realization of new ideas.

What does this tell me, this tell me that there is no relation between Ideas and the extra ordinary results which every founder is look towards, then why waste time looking for a needle in a haystack.

As a startup founder who identified a big pain (Fragmentation of Operating Systems for Applications to be developed on - It does not make financial scence to develop the same functionality three or more times) about 2 years back and started working on a solution to solve my own pain, i have come to the conclusion even after solving the problem, financial success will not come easily by just working on a Idea. But Working on this Idea made me understand how to get success.

Just follow in the footsteps of the YC. What does YC do, it enables and guides others start on the path of founding a startup and takes a % if you succeed. Since the returns are extra ordinary, even if a few succeed they win.

A example: Any developer can just start doing Minimum Viable Prototype (1 to 3 months effort for a capable person) for any interesting idea for 1% non dilutable equity return (!Don't spend any effort after MVP and don't ask for money to do the prototype!) which others are interested in pursing for a mythical return. This is equvalent to emulating YC and may have a better return on effort. Of course if all the people whom you sponsor are duds, your expected return will be zero which is also what YC is solving, If their luck is so bad that they don't have home runs, they would have wasted their money, where as you would have enjoyed trying to solve interesting problems even if they have failed and in the situation your MVP becomes a Instagram. Your 1% is 10 Million dollars.

All the above are assumptions which i am planning to verify (But not a a developer but as a Micro Angel) and hope to see what will happen.

If you earn based on Effort you are an employee, if you earn based on the value created by your Effort you are a consultant or most of the current startups, but if you earn based on other peoples effort willingly parted, then you are true scaleable startup which has a higher probability of success.

If your idea can make others succeed in what ever they do, but there is a link to return based on their success of their idea, the probability of making extra ordinary returns becomes possible.

AirBnb succeed because it is an idea which makes others monetize their living space. YC succeeds because YC shows the path to wealth generation for founders even if 50% of founders fail.

Last point is about Idea about Pets which pg assumed is a bad idea. My take on it is (I have no domain expertise on this), Pet Foods is a multi-billion dollar business, i know there are many pet food stores selling pet food, i also know that the pet food suppliers are multi-million dollar corporations. If i create a simple Mobile Pet Food Cataloging/Ordering/PreOrdering system (a 3 months effort) and give it away free to these pet food stores for giving to their customers and collate all these data and can sell the viewing of this data to the pet food supplier, I have a just in time inventory replenishment system. So many inefficiencies can be remove by asking the customer to preorder pet food. You remove overstocking, managing discounts. You effectively become the middle man between the Pet food supplier and the Pet Food store/Customer. I am not saying that this is a good idea, but just rejecting an idea because pets.com was a flop is not the correct way to go about it. You should deeply think about any idea before discarding it.

A disciple of pg giving an alternative viewpoint.