NIS 2012 Product Activation at Checkout?

So, the subscription for my current security solution expires next month.  I noticed today that Staples has a good deal on NIS 2013, so I figured that I would buy it there today and then install and activate it next month when my current solution expires.  I have done this before and not had a problem.  My 1-year subscription would then begin when I install the product and type in the Product Key.

 

However, when I went to pay for it, the lady at the checkout informed me that this product would be activated as of today.  Thus, my 1-year subscription would begin today, instead of next month, effectively reducing my subscription period by a little over a month.  She said they changed activation to the checkout time in order to prevent theft.  I decided not to buy NIS 2013 today as this seemed unreasonable.

 

My question is, was the lady at the checkout correct?  Does activation now occur at the time of checkout, or does it still happen after I install the product and type in the Product Key?  I am in Canada, if that matters.