2) "No one anymore uses "tell a friend" scripts now." - I have the stats to prove you wrong. A number of people use the "Email friend" script on our site everyday. We also know that a high percentage of people who receive the emails end up buying something. The conversion percentage is much higher than any other type of referral.
In this day and age, when "Digg This"/"Facebook It"/etc. links are readily available for injecting into your preferred social media, which can reach a much higher userbase, I've never seen very high usage of any sort of script if they are available. I like to think that I maintain a large userbase of connections to people and I can't even remember the last time I received an e-mail inviting me to check out a link (that was legitimate, we've all received links that are promoting spam/malware) sent to me by someone over e-mail unless it was copied+pasted and sent directly by them. I can't count the number of links I've seen over the past few days that were shared over IM, IRC, forums, aggregate sites (Digg, Reddit, etc.), social networking, and more. Lunarpages itself has seen the advantage of these resources and has our very own Mitch working on them.
3) ""Tell a friend" scripts have a nasty reputation of being used for spam" - Reputable companies don't abuse the trust of their customers, and understand that trust is more valuable than any short term benefits of sending spam. We never have and never will use the emails provided through our "Email friend" script to send anything. I'm sure we are not alone.
Sure, reputable companies don't. However, would you be willing to vouch that every site out there that has a "tell a friend" script on it is reputable and is using it for a legitimate purpose? With the huge influx of spam today, how many people are willing to give their e-mail address out to a random stranger on the off chance it will get them more spam? That's the #1 to get spam -- post your e-mail address out in the open where 'bots can harvest it. Unless I can see where the e-mail address is going, I have no way of knowing who will see it nor what purpose it will be used for. If I sign up for a forum or online service, I have to take a risk, so if it looks dodgy I'll use a junk mailbox, probably something like dodgit.
4) "being exploited to send spam" - I know there are poorly written "Tell a friend" scripts out there that can and have been exploited. That doesn't mean all "Tell a friend" scripts are easily exploited. Is there any type of technology or tool on the Internet that has never been exploited? If we stopped using a whole classes of things because one or more of them were exploited, there would be nothing left. We've been using our "Email friend" script for a few years and have never had any issues.
There is not a tool or system out there that cannot be exploited. As someone who also does penetration testing and auditing, and someone who's worked at another webhost, I can tell you that, as a fact, the first thing any kiddie runs for are e-mail scripts, and use them for spam. Plain and simple, it's for the money. Spam earns money. I've seen dozens if not hundreds of e-mail scripts get exploited to send out spam, and when that happens, everyone on the server suffers.
I'm not accusing anyone who's using such a tool to be a spammer, that would be baseless and inflammatory. However in recent years there is a decline in the usage of the tool for all the aforementioned reasons. Look at any major site that I've linked to. Better yet, I'll give an example:
http://www.wired.com/wiredscience/2010/02/new-3-d-map-of-the-interstellar-gas-around-the-sun/Wired is a very popular science and technology magazine, with a smattering of tech pulp. All of the "share" links at the bottom of the page are for aggregate sites along with links to the social networking sites where Wired is (ie, Twitter).
Simply put, 'e-mail a friend' scripts are becoming a relic, a tool that used to be useful back when the internet didn't have the unchecked problems it does now. They're becoming as dated as ISA cards and daughterboards.
