There are COUNTLESS ways to obtain referrals. Check back often as I will continue to update this section of the site.

1.) Tell your family and friends - It sounds too simple, but the truth is if you believe in the service you're offering then there is no way you shouldn't spread it around via word of mouth or e-mail to your family and friends.
2.) Throw up some flyers - put some flyers on car winshields and on dorm room doors, bulletin boards on college campuses, and places of business. If you have something good to offer people, show them the way.
3.) Post in Forums - Use your signature links to your advantage. Join some forums and have a signature linking back to your site.

For people who like to use signatures to get referrals - most of them take the wrong approach. Most join some sort of money making forums and start right away not necessarily spamming, but finding every thread they can to mention their success with so-and-so GPT program. The key people is to build up some credibility on the forums you join AND then start putting your referral link in the appropriate places once you've shown people you are reliable and know what you're talking about.

Also, with money making forums you're going to run into two things:
1.) People are already signed up for the site OR
2.) This one is probably more likely - people are turned off by the idea of GPT sites because they're so convinced that you can't make money for FREE (or that it's merely pocket cash - which it is for some). Let's be honest you can't earn the kind of income you could if you created your own product (i.e. ebook, etc) and used sales pages, herd marketing, etc to sell your info product for $47 dollars IF people are indeed buying said product. (That's a loose example mind you).

Try other forums like poker forums, I know a lot of people that have good luck with gaming forums.

4.) Give them an incentive to join your program - Reward the person that earns you the most commission by giving him $10 dollars to his paypal or something simple like that. Chances are he made you more than that and it will make other people want to beat him/her as your top referral so that they can win that $10... just something small like that can incite competition and get things moving along.
5.) Give Away free reports with links in them back to the site you're promoting.
6.) Start building a list of people that are interested in what you have to offer with a lead sales page and then promote your site to that list - Why wouldn't they join if it's a FREE GPT site?
7.) You need your own product, even if you just give it away to attract attention to your primary online focus and you can use private label rights products, with virtually no risk, to do this. I have some I will sell you for less than $5.00 if you're interested.
8.) Host a podcast or create your own videos. People are especially attracted to things like this and it's a GREAT way to get referrals. It really isn't that hard to get up.. it's all about attraction marketing.
9.) You want to learn more ways and gain more valuable insight into ways you can obtain referrals? Making Money Forums