Top 3 CPA Niches

If you want to start a profitable online business with the best chances of succeeding out the gate; you can't go wrong entering a market that is already proven to be profitable.
The idea here is you want to go into a bigger market that has longevity. An example (as you'll see below) is the fitness and weight loss market vs the Keto market. If you focus a business around the fitness and weight loss market you'll always have an audience. You can market and promote the hot trends of the day, but when those go away you can easily move onto the next big thing. If however, you go to narrow and build a site and audience just on the Keto market, when the health trend ends, so does your business. These are the 3 Most Profitable Mega Niches on the Internet:

Dating & Relationship

Whether someone is looking for love… is into online dating… or is in a relationship but struggling and looking for a way to rekindle the passion, a whole range of products in the dating and relationships niche are there to help. People always need advice when it comes to this area — one of the essential elements in life but so difficult to navigate.
Possible businesses here include promoting dating websites, many of which offer commissions to marketers who send them new sign-ups. You could also promote “pick up” guides, books on building stronger relationships and communication, and more.
This is a niche where there is plenty of opportunities to even niche down further. You could approach dating for straight couples, dating for gay couples, dating and relationship for certain religious groups, etc... the possibilities here are endless.
Dating and relationships, whether for single people, couples, divorced people, etc. will always be a huge niche market that sells and is full of profit potential.

Wealth & Making Money Online

Let’s face it, people want to make money. And they know that stocks, bonds, options, forex (currency trading), futures, and other investment products are a way to do that. They’ve seen the news and all those hedge fund billionaires and super-successful investors cashing in. They want to get in on the action.
Unfortunately, most people don’t really know what they’re doing. So they have to educate themselves. They need advice on which investments to make. That’s where a variety of products related to investing come in. Trading services, financial newsletters, trading systems… all different ways that show people how to invest successfully - whether it's basic budgeting and investing advice or advanced day trading strategies and speculative penny stock recommendations.
This doesn't have to be high level investing and complicated financial matters, this could simply be basic budgeting and saving as mentioned above. There are some people who have built six-figure businesses just teaching people how to save more money with coupons!
Whether the market is going up, down, or sideways… whether it’s a recession, depression, or boom time… bull or bear market… investment products do well. Because people always want to make money in the markets and you do so no matter how the economy is doing.
Even this field is constantly seeing new opportunities; right now Bitcoin and cryptocurrency are hot topics people want to learn more about.

Health & Weight Loss

Health is closely related to the fitness and weight loss market and there is some overlap, but it’s different enough to merit its own entry onto the top 10 list.
People these days more than ever are taking their health into their own hands. They don’t automatically trust what the government or their doctor tells them about their health or what they should do to be healthy. You’ve seen products in this niche everywhere: gluten-free, herbal remedies, supplements, detoxing… healing arts and products of all types. Anything that will promote a healthy lifestyle that helps avoid disease and makes you live longer.
Alternative health is extremely popular here. We’re not talking about mainstream medicine. These are cures and alternative treatments that the pharmaceutical companies don’t want you to know about after all.
The opportunities to profit here are endless: books, supplements, information products, physical products, coaching, etc.
Another thing to keep in mind is that there are always going to be new growth areas in this market. Right now medical marijuana and CBD oils are an emerging trend in this field. Unlike most other niches where having a certain level of expertise isn't required, it could be helpful to either be an expert or team up with an expert in this field.