Apply to join the YouTube Partner Program when you feel confident in the interest and following your videos have garnered. There is no set following numbers needed to become a partner, but YouTube must see that your videos have interest and are growing a following before you're accepted. Sometimes YouTube will contact you directly about becoming a partner, especially if your videos have gone viral quickly. If not, you can apply on the YouTube partner page by entering personal information, describing a marketing plan, and defining your video genre.
But there is something the company could do immediately to improve the situation. YouTube knows that I—and tens of millions of other people—have watched lots of videos made for toddlers, but it has never once recommended that I switch to YouTube Kids. Think of how hard Facebook works to push users from Instagram onto Facebook and vice versa. Why not try to get more families onto the YouTube Kids app? (Malik Ducard, YouTube’s global head of family and learning, said in a statement that YouTube has “worked hard to raise awareness of the YouTube Kids app through heavy promotion. These promos have helped drive our growth. Today, YouTube Kids has over 14 million weekly viewers and over 70 billion views.”)