A subscriber is a follower by another name, except on Twitch, where a sub is a paying customer. YouTube and Telegram use the word for a free follow. Twitch uses it for a monthly payment. Same word, two completely different things, and mixing them up misprices both.
On YouTube, subscribing costs nothing: it's a follow. The count is half of the Partner Programme's entry gate, next to watch hours, and it's the first number anyone reads on a channel. Growing it is the same game as followers everywhere, including the bought version.
Telegram channels call their members subscribers too. The subscriber count is the number on the channel's door, and since Telegram has no algorithmic feed, that door number does even more of the persuading than usual.
On Twitch, a subscription is money: a monthly payment to one channel, in three price tiers, with Amazon Prime members getting one free sub to spend each month.
Subs are how Affiliate and Partner channels actually earn. So on Twitch, "how many subs" is a revenue question. The audience-size question uses the FOLLOWER count, which is why Twitch followers and Twitch subs are completely different products.
YouTube copied the paid model as channel memberships (join buttons, badges, perks) but kept the word subscriber for the free follow.
So a YouTube channel has subscribers (free, public count) and members (paying, mostly private count). When someone compares YouTube subs with Twitch subs, they're comparing a follow with a payment.
Check the count against activity. A channel with 100,000 subscribers whose new videos get 800 views has an old, cold list: subscribers from years ago who stopped watching. The count is history; view counts and watch time are the present. Both matter, and they answer different questions.
Yes. Subscribing on YouTube is a free follow. The paid thing on YouTube is called a channel membership.
Twitch subs come in monthly tiers (with prices per country), and Prime members get one included sub per month. The streamer receives a revenue share.
1,000 subscribers plus either 4,000 public watch hours in 12 months or 10 million public Shorts views in 90 days. A lower fan-funding tier starts at 500 subscribers. Details live under the Partner Programme.
Every definition lives in the full glossary, and the services behind the vocabulary are on the services page.