Write a blog. If you have a business, consider starting a blog as part of your marketing plan. You can write how-to articles, product reviews, answers to questions and posts about upcoming events. Blogs give you more flexibility than other forms of social media like Facebook or Twitter because you own the content and aren’t bound by a third party’s rules or restrictions. Also, if your posts include keywords or phrases and link to internal and external content, you can improve the search optimization of your website. Blogs drive sales because you can include product information and links to product pages. 
Last but not least, you can also earn money online by building an online community, although the monetization strategies you can pursue will vary a lot depending on your goals. You can build a community with a blog, for example. You can also build an online forum and charge people for membership. You could even build up a Facebook group and use your influence there to sell and promote products.
One of the cool things about Google AdSense is that it's so easy to get set up. If you have a blog or website, you can sign up for a free Google AdSense Account. From there, Google will give you a unique code that you will paste onto your website. Google takes it from there, tracking your page views, traffic, and earnings on your behalf. There is no upkeep or maintenance to get this thing going, which makes it a no-brainer if you have a website already.