Why does everything expire today?
Q: Why does it seem like every deal I find expires today?
A: A favorite tactic of Internet marketers is to find a source of what they would call pain - or create one, if no legitimate pain exists - and apply pressure to it until they get what they want. In most cases, what they want to get is a sale, and by appealing to areas of pain that their visitors are experiencing, they're trying drive sales.
One of these areas of pain that they try to hit is urgency. By making you think that the “special price” you're being offered expires the very day that you're looking at the page, they're going for the quick sale. After all, you don't want to buy it tomorrow when the price goes up by a hundred dollars, right? Of course you don't. At least, that's what they're hoping, so they make it look like their offers end today to try to force you into immediate action so you don't miss out on something.
In short, you're being lied to. The offer probably doesn't expire today, whenever today happens to be.
Now, for the more technically-minded of you out there who want to know how they're doing this, it's usually just with a simple date script. It's not like they're updating the HTML on the page every day. Something like this in PHP:
<h2>Hurry! Offer expires <?= date("F jS, Y") ?>!</h2>
Would yield this when you look at the page:
Hurry! Offer expires September 7th, 2010!
Now you can lie about when your special offer expires, too!