Hey. Yes you can use just one website to promote multiple affiliate programs, but I’d say that your website should focus on just one niche. So you mention, SellHealth, that would lead me to believe your site is about health and fitness. I would then advise you to stick to that niche rather than promoting unrelated products like dog leashes and fashion accessories.
In 2006, the most active sectors for affiliate marketing were the adult gambling, retail industries and file-sharing services.:149–150 The three sectors expected to experience the greatest growth are the mobile phone, finance, and travel sectors. Soon after these sectors came the entertainment (particularly gaming) and Internet-related services (particularly broadband) sectors. Also several of the affiliate solution providers expect to see increased interest from business-to-business marketers and advertisers in using affiliate marketing as part of their mix.:149–150
More than half a billion products are sold on Amazon every month, making it an incredible opportunity to make money online. But, like everything else that involves making money online, you have to do quite a bit of work to earn it. One option on Amazon is to find products that are already made and buy and sell them at a discount. For example, you could research generic products such as clocks, keychains and mugs to attach to your brand.
What It Is: Many companies pay online testers to make sure websites are intuitive and easy to navigate. "You basically follow the instructions you're given to check out the website," says Anna Thurman, founder of RealWaysToEarnMoneyOnline.com, a site that has reviewed more than 500 online work opportunities. "It usually only takes about 15 minutes per test." Thurman recommends registering with 10 to 12 different companies since the opportunities to test these sites are doled out first come, first served. "There are people who make $100 to $200 a month by staying on top of those tests," Thurman says.
Since you’re essentially becoming a freelancer, you get ultimate independence in setting your own goals, redirecting your path when you feel so inclined, choosing the products that interest you, and even determining your own hours. This convenience means you can diversify your portfolio if you like or focus solely on simple and straightforward campaigns. You’ll also be free from company restrictions and regulations as well as ill-performing teams.
Forms of new media have also diversified how companies, brands, and ad networks serve ads to visitors. For instance, YouTube allows video-makers to embed advertisements through Google's affiliate network. New developments have made it more difficult for unscrupulous affiliates to make money. Emerging black sheep are detected and made known to the affiliate marketing community with much greater speed and efficiency.
If you're serious about making money online, start a blog. Blogging is one of the easiest and most sustainable income sources. As long as the blog is setup the right way, in the right niche, with the right content targeted at the right audience, and the offer is complementary to the content, you could make a tremendous amount of passive income from a blog.
Take surveys. You can earn $50 to $100 per month in cash and products by taking online surveys. Find survey sites by searching for “paid survey sites” online. Sign up for several survey sites to increase your chances of being selected for higher-paying surveys. Register with an email address, and check your email often so you can respond quickly to survey offers.
Fiverr is one of the biggest providers in the gig economy on the web and you can sell a wide variety of services and products through this medium. Do the research and find out what you can offer. However, keep in mind that like any other money-making task, it takes time to succeed here. And stellar reviews will help you generate more and more income over time.
Market your course: The beauty of using a course to make money online is that you can continue to sell it for as long as you’d like. Look for niche communities on Facebook, LinkedIn, or Reddit that might benefit from your content. Guest post on relevant blogs and sites. Look for anywhere you might be able to get in front of the right people. With just a few hours a month you can continue to generate sales.
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. 
Etsy: While Etsy's popularity has declined recently, it's still a great resource for selling handmade items online. No need for complex ecommerce sites or merchant accounts or any sort of automation. The company takes a commission of every sale and charges a small listing fee per item. But many still use Etsy as their primary source of income. The best part is that you can also sell digital products on here such as poster designs.