Promoting a Telegram channel in already promoted brand asia cell phone number list representations in other social networks is a working and popular strategy. First, you fill Telegram with a primary audience that is already familiar with the brand, and then the attracted subscribers spread it further by word of mouth.
Contextual advertising
You can use paid channels for contextual advertising to attract the target audience. However, there are some restrictions. For example, VKontakte contextual blocks theoretically do not prohibit posting announcements on Telegram, but in practice such advertisements may not pass moderation.

Pay to have your content posted on popular Telegram channels or bots. This tactic can yield good results if you choose a popular and active channel or bot that is aimed at your target audience.
It is important to remember that a successful Telegram promotion strategy often combines both free and paid methods. Regularity and quality of content, as well as pe