indyank - 4:24 pm on Sep 23, 2010 (gmt 0)
majestic12 - See whether this will work out for you.
Have one unique url for each product (mobile phone deal) and keep updating it with the current deal while archiving the older ones. For example, if there is a "<brandname> mobile phone deal", I will have one unique url for it, say, with the slug "brandname-phone-deal". I will always updated this page with the current deal.On expiry, this will have a slug say "brandname-phone-deal-2009".