A fitness site can have numerous revenue streams. Create healthy eating plans and recipes and lock them away as premium content. Promote and sell a fitness training course, eBook, or a series of videos. Or advertise your own personal fitness services on your site. Topfithub is  a good example of a fitness site with decent video content alongside product reviews.
Tip: Aim for products with reasonable commission. No lower than let’s say 40 percent, to make your efforts worthwhile. Also, you should note that ClickBank deducts transaction fees from a sale. Here’s a calculator to help you calculate your actual commission. More so, you need to remember to disclose all your affiliate links and mark them as nofollow. Here are a few reasons as to why you need to do this.

Find work. When you first start out, you may have to accept work writing about a topic you don’t find all that interesting. You must keep an open mind and be willing to accept work that may not be in your desired field. However, as you continue to write, you not only learn about more topics, but you also build your reputation. With time, you can be choosier about assignments you want to accept.[19]
If you have a fondness and talent for taking pictures you can make extra money online by becoming a stock photographer and selling your images to a stock photo company like ShutterStock or iStockPhoto. You’ll get royalties every time someone licenses an image you’ve submitted. To really be successful, build your own photography website to be able to showcase your portfolio and start getting higher-paid private corporate work.
While joining affiliate programs is a free opportunity, it's a business – and like any business, it will cost some money to start and run it. But those costs will be associated with building, running and promoting your blog or website. There are many tools – free and paid - you can use to assist you with all of these processes. I list a few of my favorite affiliate marketing tools here.
ClickBank is being an intermediator between affiliates and product owners where both wanted to make money. Product owners can advertise their products on ClickBank mentioning with the unique features and commission rate. Affiliates select a product based on the authority and commission rate that meets their requirements. Then they start marketing or promoting in their own way.
Mechanical Turk: Amazon's Mechanical Turk is a resource for doing human-intelligence tasks, or as the site commonly refers to them, HITs. You get paid a very small fee for any given HIT and you'll need a good deal of volume to make a substantial amount of money. But it is a resource you can use in your spare time to generate a small income online. 
Many new users prefer to start off with the 100% Free Offers, which is what we usually recommend. These offers are great for beginners because nothing is required other than several minutes of your time. The payouts on these offers are lower, but you're not paying a dime to complete them and they'll get you use to the CashCrate system. After you've started making money online with our free offers, you can always move on to trial offers and increase your earnings.
Another way to utilize your talent and business skills is to run corporate workshops online. Businesses are always looking for unique ways to help educate their workforce, and if you can package your talents into a day or half-day long session, you can sell that to companies all over the world to make money online. Start by building a portfolio and then reaching out on LinkedIn to influencers at relevant companies to see if they would be interested in you teaching their team.
If writing books interests you, an option you have is to self-publish eBooks and paperbacks with Kindle Direct Publishing, and reach millions of readers on Amazon. Publishing takes less than 5 minutes and your book appears on Kindle stores worldwide within 24-48 hours. One can earn up to 70 percent royalty on sales to customers in the US, Canada, UK, Germany, India, France, Italy, Spain, Japan, Brazil, Mexico, Australia, and so on. One can keep control of one's rights and set their own list prices and also make changes to one's books at any time. BooksFundr and Pblishing.com are two other places to get your book published and earn money.
The problem with affiliate marketing, like many other home business options, are the so-called gurus and get-rich-quick programs that suggest affiliate marketing can be done fast and with little effort. Odds are you've read claims of affiliate marketing programs that say you can make hundreds of thousands of dollars a month doing almost nothing ("Three clicks to rich!"). Or, they suggest you can set up your affiliate site, and then forget it, except to check your bank deposits.
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