A STAGGERING $2.1 BILLION in affiliate marketing fees were paid to blog and website owners in 2008. This finding in a recent study by Jupiter Research confirms what many savvy Internet marketers have known for a while: Affiliate marketing has become one of the top business opportunities online because the startup costs are so low and the income you generate can be mind-blowing.

Affiliate marketing involves having your own site and sending your traffic to someone else's site to buy their products or services. For every sale initiated by a link from your site, you earn a percentage – an affiliate sales commission.

Affiliate marketing can be done on a part-time basis, and many are so successful that they've made it their full-time job. Equally exciting, you can get in the game in just a few hours. But how successful you are is based on the amount of time and effort you devote. Here are six tips to get you started:

1. Create a website or blog

To start as an affiliate marketer, you must have a site on which to place links to the products or services you recommend. There are many inexpensive website services such as Hostgator and GoDaddy. It's also easy to set up a free blog through services such as Google's Blogger blog network. I also use Namecheap for domains and Hostnine (get a reseller account) for hosting.

2. Decide your product/service niche

Affiliate marketers help companies and entrepreneurs sell everything from jewelry and cell phones to website services and how-to e-books. Choose an area you're familiar with or one you're enthusiastic about learning. You'll be more likely to do the work and less likely to get bored before the money starts rolling in.

3. Find products and services to promote

Many affiliate networks exist to connect merchants with affiliate site publishers who can help sell their goods. Companies such as:

• Clickbank, E-junkie and PayDotCom lead the pack in connecting the creators of e-books and software with affiliates to help sell their digital download products.
• Commission Junction is popular for those who want to sell more traditional wares ranging from travel services to janitorial franchises.
• Google AdSense, which doesn't require your involvement to result in a sale. Your income is realized on a pay-per-click basis, just for leading your traffic to click to a merchant's site. PPC affiliate programs pay a lot less than programs where your referral must result in a sale. Keep in mind that a site peppered with ads and no authority or trust can look and feel like spam, and you won't get good results.

4. Affiliate site content

There are two main approaches or business models to choose from when setting up an affiliate marketing site:

• Resource Sites These sites are focused on offering lots of how-to articles and posts, and then provide affiliate links or banner ads to click for more details. Frequently adding fresh related content is vital because it gives people a reason to return to your site – and click some of your money-making links.
• Review Sites You've tried the products in your niche, now you write them up and rate them to help your site visitors decide what to buy. For each product you review, you provide a link or banner ad that clicks through for sales on your merchant partner's site. Less frequent content updates are necessary – just tweak your site about once a week to let the search engines know your site's still alive, and always try to build links.

5. Affiliate sites must attract lots of targeted traffic to succeed

Most people visiting your website or blog won't click your affiliate links. That's why it's crucial to employ a mix of marketing tactics to increase traffic – highly targeted traffic – to your site.
There are four main ways to get more site exposure and attract more potential customers:

• Paid Advertising: This is most effective when your ad copy headline, call-to-action message and graphics come together just right to compel people to click through and buy.
• Free Advertising: Sites like Craigslist and US Free Ads are but two of many popular places that accept links and banner ads for free. These tend to be affiliate marketing sites themselves, earning the owner money whenever you click their ads.
• Article Marketing: This popular marketing method offers several benefits. You're building credibility as a reliable source in your niche, gaining a higher search engine ranking by increasing the number of links leading to your site, and pulling traffic to your site. Work in an organic manner and don't spam using software engines. Ezinearticles is a great place to begin.
• E-mail Marketing: Every visitor to your site is valuable, so capturing their names and e-mail addresses to stay in touch is important. Many people might not buy your affiliate products until the third or fourth time they hear from you. So it's crucial to place an opt-in subscription box on your site for people to start receiving a weekly or monthly newsletter from you. My personal favorite is aweber, but many quality ones exist.

6. Learn the ropes in forums

These are online communities of likeminded people who exchange insights and ideas. Join at least one of these free affiliate marketing forums to benefit from advice shared by other newbies, intermediates and gurus alike:

• Digital Point: Huge, with about 25,000 active members. An excellent place to learn affiliate marketing tips, plus other techniques that impact your success such as link building and SEO.
• aBestWeb: One of the largest affiliate marketing forums, with nearly 100 sub-forums. Covers the broadest range of affiliate marketing-specific subjects, with heavy participation by numerous go-getter merchants and serious affiliates.
• Warrior Forum: A killer networking forum for beginners and advanced alike. Set up a profile, start participating, ask questions and promote as well.

To do well, read all you can about the opinions, tool and strategies of both experts and peers. But before you even start, choose a niche about which you're passionate. The more you truly enjoy what you're immersed in, the more likely you are to transform your affiliate marketing and money-making venture into a huge success.

Jon Rognerud is Entrepreneur.com's SEO columnist, an SEO consultant and the author of The Ultimate Guide to Search Engine Optimization, available from Entrepreneur Press. He has more than 20 years experience building marketing and web projects, including creating content and application solutions at Yahoo!/Overture.