Do you have to spend money to make money? It depends. It helps, but it isn't necessary.

You can start a blog, for instance, at WordPress.com or Blogger.com and it's free. Then monetize your blog with Google AdSense. Chances are, you won't make $100 a day from that one blog, even if you have high value keywords, but if you can make $5 a day from Google AdSense and duplicate that effort 20 times then you'll hit your $100 per day goal. But do you really need to do it through Google AdSense?

No. There are other ways to make money online. Here are five different ways that you can make money online and hit the $100 per day mark within a year or two:

1. Start a service business - I mean, really start a service business online. I am a ghostwriter and currently manage more than 50 blogs and oversee a staff of writers. I make more than $100 per day. You can too if you use your imagination and have the drive to build a business from the bottom up.
2. Become an ad watcher - It's true. You can click ads for a living and make more than $100 per day. It takes time, but you'll have to build up your network. Services like Neobux will pay you .01 per ad to view it for 30 seconds. That's not a lot, but you also get paid on the ad views of people you recruit and, no, it's not MLM. It's one level of recruitment and you get paid on the views of everyone that you recruit directly. At 5 ads per day you'll need to recruit 4,000 people to make that $100 per day at the most basic level of membership. Upgrade your membership and you'll only need to recruit 2,000 ad viewers. Is that difficult? You bet. Get a blog and optimize it for search traffic and you can hit your goal.
3. Sell a product - Do you have a unique product? Put up a website and optimize it for search traffic. Sell the dickens out of your unique product (make sure it's something that people truly want) and join a few social networks like Facebook to meet people interested in the same things you are in. With some hard work and good sales copy you can earn $100 per day selling your own products. Use services like eBay and Amazon to help you sell through consignments.
4. Sell your photos - Stock photo websites like Shutterstock will take your photos and sell them for you. At 50 cents per download, 10 photos per day will result in $5 per day revenue. If you have 10 photos that get downloaded 10 times each, that's $100 per day revenue from your photos. Do people pay for photos that way? Absolutely. All the time.
5. Affiliate Marketing - Another way to make $100 per day online is to find a product that you like and that has an affiliate program. Join the affiliate program and set up a website or blog to sell that product. Promote your site with articles and other traffic driving methods like search engine optimization and social media. You'll have to work hard, but with time you can make $100 per day selling products online.

Nothing comes easy. Anything worthwhile takes time and hard work. Don't settle for quick fixes and nobody ever said you couldn't diversify. Combine one or more of these methods. If you can make $50 per day selling your services, $25 per day selling stock photos, and the other $25 per day doing other things then you still reach that $100 per day goal. Above all, don't give up. It's worth the effort.