The peer-to-peer concept is coming to virtually every corner of human existence. That includes the hospitality industry. Through AirBnB you can actually rent out your house for various lengths of time for a predetermined fee. That gives you an extra income on your house and gives the visitor the benefit of having an entire house, rather than being crammed into a single hotel room.
Provide excellent customer service. Answer any questions buyers post as quickly as possible. Be professional and courteous. Positive communication builds your reputation with buyers and gets you return business. Also, package your product well and ship it out quickly. Allowing an item to become damaged or taking too long to ship can negatively affect your reputation among buyers. Wrap all items, especially fragile ones, in appropriate packaging. Commit to shipping items as soon as you receive payment.
If you’re willing to take on some risk and have the heart of a true hustler, you can make extra money online doing commission-only sales for startups and other businesses. While you won’t be getting a regular salary, with the right sales strategies and skills as an inside sales rep, you can make decent money for each sale you bring in. And because you’ll most likely be working with startups, if you can negotiate a little equity you could profit big time if you're pitching a solid product and the startup succeeds.
Dating sites and apps are extremely popular and have become more and more niche as the industry develops. They can also be very profitable, as there are many ways to monetize them. You can charge a joining fee, provide premium subscriptions, or make money from advertising on your site. White Label Dating provides a pre-built dating platform for your project. You simply choose the niche and branding for your new dating site. Once your website goes live, you just need to promote it, manage the users, and collect the earnings.
Please note that some of the links below are affiliate links and at no additional cost to you, I will earn a commission. Know that I only recommend products, tools and learning resources I've personally used and believe are genuinely helpful, not because of the small commissions I make if you decide to purchase them. Most of all, I would never advocate for buying something that you can't afford or that you're not yet ready to implement.
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. 
It’s one of the oldest and most proven ways to make money – buy low, sell high. The buy low part comes from searching garage sales, estate sales, and even thrift stores to find items that are in good condition (“gently used”) but selling well below what they would if they were brand-new. In this way, you might be able to acquire an item for $5, and later sell it for $50.
Running a coupons website can be very lucrative. Find a coupon niche, select a WordPress coupon theme, and then display relevant coupons on your site. When your audience uses the coupon codes or discount links, you will earn an affiliate cut for example you could set-up a site dedicated to iHerb Coupons or add a page to your website with Web Hosting Promo Codes. Coupon websites are quite high maintenance as they need to be constantly updated with new offers. However, if you build up an engaged audience and allow them to post coupons and discounts they have found themselves, then quite quickly your workload will reduce.
The music industry might not be as strong as it was in the 80s, but there are still plenty of ways to make money online as a musician. Sites like SoundBetter let you sell your services as a songwriter, producer, or session musician to thousands of customers a month. While Musicbed, Music Vine, Marmoset, and SongFreedom are perfect for licensing your music to TV shows, movies, and web series.
Some businesses may be interested in adding other types of paid content to your website. This could include videos, podcasts, or any other material that would work with your site and help a business market itself. Always make sure that paid content isn’t too promotional. It needs to add value to your audience first and foremost, and not just present as an advert.
Get samples. When you first start out as a freelance writer, it can be hard to get work without any published samples. However, it is possible to get quality samples if you are willing to do some writing for free. First, you can publish content on your own blog or website. Also, you can write guest posts for someone else’s blog. Finally, you can write blog posts for free in exchange for a byline.