NSInvocationOperation - Does not call method on a different thread?

So I have a service clint class that has a method called fetch. I am invoking this method using NSInvocationOperation. and when I check the thread it seems like it's callin the mthod on the main thread. Isn't the whole point of using NSInvocationOperation to run things asynchronously?

Invoking method

ServiceClient *client = [[ServiceClient alloc] init];
NSInvocationOperation *invocatopnOperation = [[NSInvocationOperation alloc] initWithTarget:client selector:@selector(fetch) object:nil];
[invocatopnOperation start];

The method in service client

- (void)fetch
{
    if ([[NSThread currentThread] isEqual:[NSThread mainThread]])
    {
        NSLog(@"NOOOOOO");
    }
     ............
}

From NSInvocationOperation class reference:

The NSInvocationOperation class is a concrete subclass of NSOperation that manages the execution of a single encapsulated task specified as an invocation. You can use this class to initiate an operation that consists of invoking a selector on a specified object. This class implements a non-concurrent operation.

This means that in order to perform an operation asynchronously you need to add it to an operation queue.