Contract length is often a indication of a good network,
in a network that is know for other good reasons a reason their contract length is long is to project earnings over multiply years and to supply more features.This is the case in most premium networks.
Then there`s the ones that are known for being bad and have long contracts to stop anyone from getting out (Acifin 5-8 years)
And then theres ones who provide more than average features and support in return for a 1-2 year contract e.g. the Fullscreen and Maker Families.
Then theres TGN, basically TGN got to the point that they were so bad they had to pull a publicity stunt , apparently they had over double on their list of people leaving than coming in... So they made the contract lenght nothing and are giving 100% payouts(actually 60/40 just phrased differently)