If you want to sell products online, you may can it by creating your own website. As there's lot of competition and several existing websites in place already catering to this market, an attempt to create a niche in terms of products may be considered. Or, you can use the platform such as Amazon, Flipkart to sell. One can increase reach and visibility through affiliate marketing.
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. 
High-ticket consulting or coaching: You could sell your own high-ticket consulting or coaching products from your website. You'll still need a website, merchant account, sales funnel, lead magnet and many other items. But you can easily earn a substantial amount of money from each individual customer, making it well worth the arduous setup required.
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.
Every year, hundreds of millions of documents are notarized in the United States: wills, mortgages, citizenship forms, handgun applications. While for decades, this has all been done in person, there is a budding crop of sites that allow notaries to take their services online. If you’re already a notary, you can sell your services online. Or, if you want to get started, check out the National Notary’s checklist for becoming a certified notary.
The first follows the startup path we outlined above: You have a disruptive idea for an app or piece of software, you validate the idea with real customers, and then raise money to hire developers or a development studio to build, launch, and scale your software. If you’ve done everything right, your software will be accepted to the Apple and Google Stores and you’ll make money every time someone downloads it or pays for a premium feature.
If you want to help shape products in their early stages, joining an online focus group or answering survey questions is a great way to make extra money online. They don’t pay as much as some of the other options we’ve highlighted, but you can join groups on sites like Survey Junkie, Swagbucks, and IPSOS that pay out through Amazon gift cards, check, or PayPal. You’ll be asked to provide a bit of information about your demographics (age, location, etc…), but after that you can get going making money through surveys.
Keep in mind though, you don’t need a website to do sponsored content since you can also get paid if you have a lot of social media followers. My wife has a pretty big Instagram following, and she gets all kinds of sponsorships. Not only does she get paid in cash, but we get a lot of free stuff, too. We’ve received free rugs, free lights, and free carpet cleaners. She only promotes things she loves though, so this strategy works really well for her.