Why would/should I care? Honest question, I don't know much about the affiliation programme.

Allowing submissions with an affiliate code encourages people to submit material to HN that has no intellectually gratifying qualities (see guidelines) in the hopes that thousands click through, and their future purchases are tracked and a commission paid to the submitter.

I wanted to share this link with my Twitter followers, but noticed that there was an affiliate code in it; I did't want them to think I posted it for money.