[CONGA] Quidco
 

Quidco.com is one of the UK's largest cashback sites. Useful for UK trains for example (including Gatwick Express).

Referal bonus is £2.50, but you have to change the slider yourself to 1.25 (to you) and 1.25 (to the next person in the conga) when you generate your referal link.

Referal bonus is paid out after the next person in the conga has earned £5 in cashback.

my link: http://www.quidco.com/user/6014987/2155200/