Usually when you hear about a great sale the reaction would be to go buy the item in question as you can save a lot of money. But I was thinking today as many times when there is a huge sale for an item it can be a signal that something is happening which may not be in your best interest to buy it. Food items area great example as usually a huge drop in price means the product may be close to or has already expired. So you need to determine if the quality is still good for you.
But for items like electronics a huge sale can usually mean there is a new version coming soon where retailers are trying to clear out the existing inventory. While that sounds great initially, imagine it like a smartphone where one month later a product comes out that is three times faster than the current generation with way more features. In a lot of cases, people would have rather waited for the new one.
You should always research about products anyways before making a hasty purchase. But this is something many people overlook.