YouTube, Twitter, Amazon, etc. make money off of selling your browsing habits to marketing companies to make it easier to sell products to you. Especially Amazon.
It's why they don't try to stop adblock despite easily being able to.
It's not quite that simple. From what I can gather Alphabet companies (Google, Youtube, etc) don't directly sell your data. They sell analysis of the data, and aggregated forms of the data. They will also contract out to place your ads where they think best. But they maintain control of the raw data (because data = money = power). Like I said, it's Dirty Rotten Scoundrels.
Anyway, I know HOW they make money, but that doesn't change the fact that Youtube and Twitter took ages to turn tiny profits. And "too big to fail" companies generally don't get into the business of backing very expensive projects that only turn a small profit over a long period of time. Also Youtube and Twitter DO still get a big chunk of their funding via advertisements. They don't care about adblock that much because their target audience is mobile anyway, and adblockers are far less prevalent and effective on mobile.
Like from Google/Alphabet's position, straight fiscally it would probably have been better to invest the 100bn or so they put into Youtube into regular stocks and they'd make more money. Which implies there are significant intangibles beyond pure money (data = power) to these platforms.
The gist of it boils down to though nobody can really compete with them because the business they are in isn't actually profitable.
Gab had 465k users per wikipedia, and I'll bet a fair # of those were idle/bots. In the realm of social media that's a pittance. C-tier youtube channels have that many subs. Ninja pulled more than that for a single stream.
Also, what % do you think got monetized?
"Gab does not use advertising. The site began offering a premium subscription service for Gab named "Gab Pro" in April 2017. The subscription allows users to have private chats for up to 25 people, which was later added for all users with two users maximum and Gab Pro with 50 maximum. Messages are deleted after 24 hours. Gab Pro subscribers can also view a topic breakdown for other users, make lists of users to sort their home feed, livestream on GabTV (Gab's video-sharing service), and more easily get their profile verified. Subscribers also get a "PRO" badge next to their posts. In July 2017 Gab also started an investment project which met its goal of $1.07 million on August 19, 2017."
So their only funding was a version of gab that seems tailor made to planning terrorist attacks? I mean basically you pay to add Snapchat and Instagram features onto Gab, plus a few things Twitter also does for free.
And this is what I mean, there's no real way for a social media platform to actually make money. You have to have tens of millions of users at least to stand a chance, and each user costs you more in hosting and bandwidth, so adding people doesn't even help that much.