I haven't heard anything about this percentage sell-on clause. Interesting. Not quite sure what to make of that.
As Jay says though, if he was looking to make money off of players then he wouldn't be running the risk of losing them for nowt with 1 year contracts.
While I'm not 100% comfortable with 1 year contracts, I'd like to think Gannon will look to extend such contracts come October/November if the player has settled in well.