Their only purpose in the game is black market trade of resources.

Sometimes that seems to be the only purpose of the call.

And the only purpose in making a gun ready to use is using it.

Was that your only purpose in drawing him close to me?

One he might have enjoyed if it had been his only purpose.

Your only purpose in life is not to have to breed.

It was large, of course, but that hadn't been its only purpose.

His only purpose had been to get rid of her.

Do you want to know the only real purpose it serves?

We did not need to attack; our only purpose was defense.