The meaning may depend on the formality level of the conversation, though the very usage of it is quite informal already. While what @shabunc says may be true, this may also be a way to give a carte blanche, so to speak. Even less formal form would be:
да - так да, нет - так нет.
And the full version of the phrase in this case is:
It would be nice if you agree, but if you don't, it's fine too (though I don't see why).