Nevermind, solved this myself. In case anyone wants to know:
<?php $agent = get_post_meta( $post->ID, ‘affiliate_name’, true ); $user_info = get_userdata($agent); echo $user_info->display_name;?>
Ah, but when I place this code inside my home-template.php, its works!
But the question now is, how do I make it so it works in footer.php? I need client to be able to edit the Twitter/Facebook/Google+ icons at the footer. How does one do this?