Understand how a niche website works. A niche website focuses on very targeted, specific information. The content must be specific, useful and interesting to your target audience. Successful niche websites get anywhere from 1,000 to 10,000 visitors per month. You build content on a particular keyword, and you make passive income with Google Adsense or through affiliate links.
28. Subscription – If you think of something valuable (newsletter, online magazine, etc.) that you can consistently offer on a certain basis (weekly, monthly, etc.), you may want to offer a subscription service. This could be a fee charged each time your product is sent out or on a monthly basis. Either way, this has to be something that your customers can only get by subscribing to your website.
How many email newsletters are you bombarded with every single day? There’s a reason for that. Email marketing to an actively interested group of email subscribers is one of the best ways to make money online. There have even been million-dollar businesses built from simple email newsletters like TheSkimm, or Mister Spoils. Each newsletter targets a specific type of user with interesting, daily content, while also partnering with relevant companies and affiliates to bring in extra money. If this seems daunting, it’s not. Email marketing tools like MailChimp, ConvertKit, HubSpot and AWeber make it easier than ever to get started with email marketing. Here's my comparison of ConvertKit vs AWeber vs Mailchimp to review a few of my top picks. And another great option to consider (with the largest free plan available) is SendPulse, with their ability to send up to 15,000 emails per month to 2,500 subscribers, and then affordable plans starting at under $10/month as you grow from there.
Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
Whether you have a website or are still dreaming up ideas for a blog, you can also look into affiliate marketing. With affiliate marketing, you partner with brands and businesses within the content of your website. If you mention a product or service, you link to that produce or service using a unique affiliate code you received when you signed up for that particular affiliate program. From there, you’ll make money any time someone buys a product or service through your link.