Probably just there for legal reasons. They do mention their compensation on the site however.
> If successful, we transfer your money to you immediately. If the airline refunds your ticket within 7 days, our service is free of charge. After that, you only pay if we are successful (commission 14-28% plus VAT). For compensation claims, the commission is usually 20-30 % (plus VAT).
If it's under 7 days it's probably because the airline is just less sketchy and it's super easy for them to get the money for you. The ones that take longer are probably the ones that are a bigger pain in the butt.
> If successful, we transfer your money to you immediately. If the airline refunds your ticket within 7 days, our service is free of charge. After that, you only pay if we are successful (commission 14-28% plus VAT). For compensation claims, the commission is usually 20-30 % (plus VAT).