What is the good optimal Lockin period of internally distributed tokens for ICO?

[KarKeyan]

I know ICO's won't sell all the generated tokens during their sale. They will keep some for internal distribution like for Teams, Advisors,... Once the sale is done investors can trade tokens but internally distributed tokens can't be used for trading.

What is the best optimal period to lock tokens internally say for 2 years or 3 years? On what basis ICO's are doing it?

[mrdeposit]

Can you imagine how this might affect the price when coin is new listed? The team has already collected money from the sale, and if they dump price by selling team amount, already it is scam.