I find it can be difficult to split in some cases because they pay the bonus at my airline in phases. Paid in phases based on the longevity and performance of the referred pilot (people have different things going on in life which means milestones within the company happen at different times and not to mention the bonus is of course taxed. I don't necessarily mind splitting it but I'm sorta along the line of, hey I get the bonus by referring you. You get the bonus by referring someone else, so on and so on. I don't go back and ask for a 1/4 split from a guy I referred who later got money by referring another person. It gets a little stupid. Just keep paying it forward.