The answer: read on ManyStories
Take a look at the picture above. On the right, are the top readers from for the week in which that screenshot was captured. Those readers all have something in common: they have many followers.
Take jinglesnote for example. While on the waitlist to share his stories on ManyStories, he spent some time reading more than 100 stories on ManyStories. By the time he was allowed to share his stories, he had more than 30 followers on ManyStories.
Then there's marianne_tai. While Marianne has only shared four stories, she has attracted more than 50 followers; she's read over ~29 stories on ManyStories. She, too, was a top reader. Jack_Burt and rodrigobahadian both have shared 18 stories and have ~35 followers.
Finally, there's markmkelly who has read over 300 stories on ManyStories and has 116 followers. Of course, it helps that Mark has shared nearly 200 of his stories on ManyStories.
So the answer to the question posed here is simple: if you want readers to read your stories on ManyStories, you, too, should read on ManyStories.