It is imperative for any affiliate earning commissions to send us their W9 form as we legally need to have this document on file to be able to process payments (otherwise we will have to hold payments untill we get it).
W9 can be sent by e-mail, regular mail or fax (feel free to e-mail me to get the adress or #).
W9 can be found at http://www.irs.gov/pub/irs-pdf/fw9.pdf
So, if your commission is getting close to $25 and you haven't done so yet, make sure to send your W9 early so that your payments won't get delayed!