Though most successful businessmen tend to be quite enterprising, less of them than you might think believe that multiple streams of income can be found. The phrase multiple streams of income is attributed to Robert Allen. This is actually one of the best ways to not just become rich, but stay that way.

Creating multiple streams of income has become a reality for entrepreneurs all over the world because of the opportunities that the Internet has created and here are just some of the many ways to help you get started building your income portfolios.

1. Google AdSense

Google's AdSense program is probably one of the easiest ways for anyone, even a complete newbies, to start building a passive stream of income. AdSense is a pay-per-click advertising network that pays you every time a visitor to your website clicks on an advertisement. Apart from placing a simple piece of code on your website that AdSense provides, the only other real work you have to do is create relevant content and drive traffic to your site.

2. Create an Online Directory

Online directories tend to receive lots of web traffic due to their large amount of content. Income can be built using AdSense on such sites. Selling text links on the web page is another way to develop a passive income that is being popularized.

As opposed to more traditional banner advertisements, text links appear in the directory itself. Such links can be sold per month, year, or permanently. Using this system will help to increase your income.

If you don't want to create a directory but you already have a website, you might consider creating a category where you place links to other websites for a fee. The higher the page rank of your website, the higher the fee you can demand.

3. Get Paid to Review Products

Another increasingly popular way of creating a new revenue stream is to become a paid blogger. You simply start a blog and get paid to review products, review someone else's blog, or review just about anything an advertiser would want reviewed. Services like ReviewMe.com and PayPerPost.com caters to both bloggers and advertisers who are interested in this business model.

4. Create a Membership Site

You could start a website with a monthly fee if you believe you can offer information worth such a payment. Offer special services and content to paying members. Knowing that there is specific content reserved for members only will help build your membership and eventually allow you to raise the monthly fee.

5. Selling Domain Names

If you understand how to do it well, handling the sale and purchase of domain names can be a good way to earn income quickly. In order to make money in this way, it is important to learn about the tasks involved and how to complete them. But once you do, you will be able to join the group of people already earning a full-time income through buying and selling domain names.