Yeah I'm not sure of the efficiency or the ethicity of adding random people to telegram channels unless they want to join but you can buy subscribers or give updates to people interested through telegram.
Twitter and Facebook are often used in the altcoin sections, essentially you could offer a giveaway for people who like/follow your page and then hire a manager to check it or check it yourself...
Okay, so I could giveaway coins and the users have to follow some rules, like subscribe, like, invite 10 friends, etc. right?
I also saw “campaign managers”. Those are guys who could organize various promotion techniques on my behalf?
Yes, the best options for you is to hire a trusted and experienced manager. They can recommend you which campaign you can do and manage it for you. Hiring a trusted person means that you pass the first non-scam test because reputed managers will not accept to work for obviously scammers. Also, they will protect you and your business by users who are willing to deceive your promotion participating with fake accounts.
I suggest you talk with
yahoo62278 or find them on Telegram @yahoo62278