The founder of the messenger, Pavel Durov, wrote about this in his Telegram.
“As I predicted, 2024 has turned out to be very successful for Telegram. For the first time in its 3-year monetization history, Telegram has become profitable,” Durov writes. “This year, the number of Telegram Premium subscribers has tripled, exceeding 12 million. Advertising revenue has also increased several times. As a result, Telegram's total revenue in 2024 surpassed $1 billion, and we are closing the year with over $500 million in cash reserves, not including crypto assets.”
He also mentioned that over the past four years, Telegram has issued debt obligations totaling around $2 billion. A significant portion of this was repaid this fall, taking advantage of favorable bond prices for Telegram.