I dont know where to post this so feel free to move it wheverrrrr u want.

Just a quicky but it helped me so guess itd help some of you.
I run a large member based site, part of my process for attracting new members is giving credit to existing members who "refer" new guys.  To do this they have their own url, i.e. blah.com/register.

php

 ?refferalId=X
This is all well and good for getting people on the site but it means i have a couple of hundred or thousand links not really going anywhere

SEO

  wise.

In my

php

  i check for the $_GET['referralId'] and then set a session up to record it so if the person browses elsewhere on the site the referral stays.

A simple 301 then Header("Location: /index.html"); afterwards will ensure google treats any referral link as a link to your main home page.
Meaning not only do  you get loads of new members, your existing members take the credit, you also get full

SEO

  / Link Weight benefit.

Simple and easy but often overlooked

good point, regardless where it should go

I wonder why you arent seeing too much

SEO

  benefit.. even if they were all so/so sites.. a few thousand links should at least count for something... nevertheless... I got to hand it to ya.. thats a great idea for building a forum....

that actually is a great idea. what would probably help

SEO

  wise would be if members could link directly to posts in the forum, instead of a generic url. that way they could post relevant anchors and such which would help for ranking.

hmmmm. how hard would something like that be for smf? i dont do forums, but possibly would if i found the right topic.
i would guess that something could be added to the template file that checks for referralId and if so, register a hit in the database or whatever your doing with it.

What do they get as "credit"?

On my site its just about rep etc
We have a

ajax

  chatroom and a popup "card" over each person when you hover over them and you get to see who referred who
We are also gonna do league tables n that to try encourage more people.
But thats about it credit wise