Free Tell a Friend Services
Viral marketing has long been one of the Internet buzzwords, "Tell a Friend" or personal referral services are a perfect example of it! If someone is at your site and likes it, these make it very easy (and is a nice reminder) for them to recommend it to a friend.
Let Your Visitors Help Promote Your Website
Viral Marketing.. hmm, I bet you've heard that catch-phrase before but never really thought about what it means. Well a simple example is adding a way for your website visitors to easily recommend your website to their friends and family. These "Tell a Friend" services do just that, and seeing them serves as a nice reminder for your visitors to tell others about it as well. After all, if your site offers something of value, your visitors will want to help you promote it (even if that's not how they are thinking about it at the time), why not make it easier for them.
Bravenet
Customize the look of the announcer, make up your own announcement and type it into the simple editor. You can change your announcement at any time and put it on multiple pages of your site. They'll also keep a total of how many announcements have been sent! Very cool! They offer tons of other free resources for your website here as well!
SiteGadgets.com
SiteGagdets.com offers 18 different gadgets to spice up your website! Among them is their free Tell-A-Friend, just post a link and visitors can instantly tell all their friends how great your site is, encouraging them to come visit. What makes this one truly unique is that they pay you!
1-Hit's Free Tell a Friend Service
This is one of the few remotely hosted, free 'recommend us' services left online. It uses no JavaScript's (so even visitors with that disabled will still see your gentle nudge to tell someone about you), no pop-ups and it's totally free. A few features they offer with it are that you can edit your details any time you wish, there's an unlimited amount of pages you can send and you can customize it to perfectly fit in with your website!