Website marketing endeavor

[influx]

Hi all,

I am currently in the works of making a 'referral opportunity' program for my website. I have about 800 users signed up and am offering them premium features for six months when they refer four or more people to my website (the referral will be logged once the referred user actually logs in for the first time).

How should I structure the logging of referrals?

In my database, I have a table called USERS (id, username, password, location, etc.). Should I add the following fields into the USERS table?: referral1, referral2, referral3, referral4, referral_complete_date

In the referral rows I can save usernames, and referral_complete_date can record the date of completing the referral opportunity.

Is this the best approach? OR should I create a new table called REFS to log the referrals separately? If so, how should I do that?

The only thing I am worried about is that some referred users won't even log in, and I don't want to count that as a referral. So, I may have to create more than four rows (maybe 12) to log the referred usernames just incase some of them don't log in.

Thanks!
-influx

[dnast]

What about a table like REFS (id, user_id, referral, active)? When the referee logs on for the first time set 'active' to "true" and "SELECT count(id) FROM refs WHERE user_id = $referrers_id AND active = 'true'" to see how many referred users have logged on so far.