Also, for Twitter, it may be easy to clone the "public facing" product which is basically a list of filtered tweets from the DB with probably some tweaks for th

Also, for Twitter, it may be easy to clone the "public facing" product which is basically a list of filtered tweets from the DB with probably some tweaks for the scale. But the point is that this product is not what makes the company money. If you only consider this, sure it’s a easy to clone product, backoffice for the advertisers, algorithms to maximize engagement, external integrations, marketing, PRs, partnerships are the thing that brings money home. Of course if there was no Twitter, I imagine you could earn some money/be profitable with just the public product and some basic backend for ads publishers. But you’ll probably encounter a revenue bottleneck and start researching fresh income which you can do by … becoming Twitter, the big company.