Why is .call(this) used instead of parenthesis

Is there a particular reason why i often encounter:

(function() {
  console.log("Hello");
}).call(this);

instead of:

(function() {
  console.log("Hello");
})();

It should have the same effect when passing this to call or not?

There seems to be some performance difference: http://jsperf.com/call-vs-parenthesis.