Like many businesses, the key to building it and making it grow is consistency. If you begin your business, you need to make sure that you do two things. First, continue to add to your business. Your business will not run on its own. Second, you need to update frequently. Continue to do what you are doing and then add to it. It seems that many people want to start a business that will make you rich and then sit back and do nothing.
That is not the way it works. Therefore, PewDiePie probably earned his 95 million subscribers by building his videos. He became a little popular and then gained popularity because he was consistent about putting youtube videos on youtube and updating it and adding new material.