Well, more of a tip then a one time offer.
Kaspersky (I think) are the only Anitvirus / Internet Security software co that not only allow updates of the virus databases during the license period but the whole software package to the latest version.
So, if you have Kaspersky 2012 you can upgrade to the latest 2013 version for free.
Now, given that the 2013 version costs £30 odd for a 3 license package from Amazon and the 2012 version only £12 there is quite a saving to be had.
All you do is buy the 2012 version but download the 2013 version from kaspersky.com and then enter your 2012 license key.
This also works for license renewal. So, your year is up and its nagging you to renew the license. Simply buy a cheap 2012 copy (2011 and earlier will probably work also but I've not tested those), pop that license key into the nag box and you're done.