I think you're underestimating the number of businesses who could be convinced that $12 a year is like the marketing equivalent of Pascal's Wager.

50 countries with 200 persons each?

I'd say more than 10.000 in just USA alone. Even if you up it to $5 a month. Twitter is used a lot by those who use twitter.

I'd say 10,000 from businesses in the USA alone. A lot of companies use twitter as their makeshift tech support and public image. $1/month for a company is completely irrelevant to their spending.

Me. If I still used Twitter. Heck, I tweet maybe 5 times a month and I'd pay that. $1 a month is so cheap I would notice.

You'd likely notice the first time it asks you for payment.

On iOS it takes a single TouchID auth and a few message prompts to sign up for a recurring subscription - you won't ever be asked for payment again. I'm certain Android is similarly streamlined.

You must be joking.