Although I am not currently in any Programs, I have in the past joined many Affiliate Programs.

Getting referrals and sign ups can be very difficult at times.  The best ways that I had discovered to get referrals were these following methods:

1.) Paid To Read Emails - When you join these programs, you are paid to read emails, very little, but you are paid.  You can choose to cash out your small amount (usually $2 give or take) or Redeem it for advertising.  I would choose to redeem for advertising.  This way you are basically guaranteed that many will read your advertisements, because they want to earn for reading their mail also.  I received many sign ups this way.

2.) Social Networking Communities - When you join these, you do not want to spam.  You want to get your feet in the door by learning about the Community and making friends in the Community.  Spamming will get you nowhere, but those you make friends with will usually check out what you have to offer. (Ah, the power of friendship) :)

3.) Blogs and Websites - If you have a blog or domain, post as much information as possible about your Programs.   

In the good ole days, you would receive money just for sign ups, and/or commission from your downlines, without any out of pocket expenses. 

Now days, programs such as SFI, you can not earn from your downline if you are not a PAID member.  Thus you must pay $20 a month and hope that you will earn that $20 back.  I actually consider this a rip off, but I am sure many would disagree with me.

There are many scams out there, and the scammers are getting better and better at blending themselves in with the logical ones.  It's nearly impossible to distinguish the difference at times, that is why I no longer participate in any of them.

However, for those of you that are in such Programs, I wish you the best of luck and I hope that my tips will come in handy for you.