The 18-year-old model, who has worked for Chanel and makes her debut appearance in the new June edition of US Vogue, has approximately 7.99 million fans on the social media site, more than half of which are reportedly fake or "inactive" accounts.
A source told In Touch magazine: "Kendall and her sisters have bought a good amount of their followers."
The insider claimed that the young 'Keeping Up with the Kardashians' star, who recently splashed out $1.39-million on her first home in Los Angeles, deliberately boosted her number of followers in a bid to appear more popular.
Kendall allegedly gets $1 000 every time she tweets about liking a product or item of clothing.
Another source said: "She knows the more followers she has, the more she'll get paid to tweet."
Kendall, who was previously linked to Harry Styles, acted as bridesmaid at her half-sister Kim Kardashian West's wedding to Kanye West in Florence, Italy last Saturday.
She told Canada's 'eTalk' in an interview set to air tonight: "It was beautiful. It was filled with a lot of love."
Her younger sister Kylie Jenner, 16, added: "We can't say much, but it was amazing."