YouTube is the second most media where people spend their time after social media channels like Facebook, and this has turned out into a most trending way to generate good income online. You can start your earning by creating a YouTube channel and become a partner of YouTube to earn money online through YouTube. Earning money through YouTube is not a tough play. Trust me, you can earn money online from home without investment except your time.
The topic you choose must have enough depth that you can create a lot of content for it. This is important for building an authoritative site, for search engine optimization, and most importantly, for the end user. If you don't have enough content about a topic, you're not going to be taken very seriously as an authority on the topic and it's unlikely you can convince someone to make a purchase from you.