Actually all sites are like that. Just as there are in store specials for a particular day if you happen to come in the same holds true for online sales specials not in the retail store. Online sales are there to draw people to start buying from a website and usually is on certain items only just as you would find for an in store special for a particular day.
Personally I'd rather get it online if I can instead of having to drive some 25-30 miles hoping I will find what I want on sale.