'spread the popularity' is correct and usable in written English.
You can use it to talk about an idea or concept gaining in public knowledge, approval, or acceptance. For example, "The singer's music video, released on YouTube, helped to spread the popularity of her new single around the world."
The rise of YouTube is widely credited with helping spread the popularity of parkour.
During the 19th Century migrating Cornish miners helped to spread the popularity of the traditional pasty in America and Australia.
Appearances on "Saturday Night Live," in 1981, and in Gus Van Sant's "Drugstore Cowboy," in 1989, spread the popularity of his gentleman-junkie cool.
But for sponsorship, for TV audience, to spread the popularity of yachting to the world, it is vital to know where to go and when to go.
This could spread the popularity of the game even further; and it would certainly mean that staging the semi-final and final of the competition would be open to a far wider range of countries.
The series, Catch a Fire, begins with the Pascal Légitimus comedy "Caribbean in Paris" and includes "The Harder They Come," the Perry Henzell film that spread the popularity of reggae and catapulted Jimmy Cliff (above) to stardom.
It would have also been nice to see segments on Shanghai Tang and Vivienne Tam, the two brands that have done the most for spreading the popularity of the Chinese dress internationally.
Italy has been credited with spreading the popularity of gelato throughout Europe and the rest of the world.
The company admits nostalgia has played a part in spreading the popularity of the stickers beyond its "core audience of boys 5-15".
But no one's made more of an impact in spreading the popularity of New Japan in recent times than the young, foreign Junior heavyweight stars Ricochet and Will Ospreay.
Popular Science published a four page article on sailboarding, which helped ignite a fire that spread the sport's popularity overseas.
