Most people need deadlines in order to take action.
Imagine a business saying "We're offering 40% off all our products for the entire year of 2018!"
Most people wouldn't jump on the offer, because they have an entire year to make a decision.
Giving people a deadline on taking action is crucial to getting a sale. Whether it is on Etsy or in any other business. People take action when they are given a limited time to respond.
That's why so many businesses say "Call Today" or "Shop Now" or "Get 30% off everything this weekend only." Because people need some urgency in order to make a decision. Otherwise, they'll put it off, even if it's an important decision they need to make. People just tend not to take action unless something is urgent.
So when you are selling on Etsy, it is really important to constantly use deadlines and urgency to motivate people to buy from you.
Typically, anything longer than 1 week, or 7 days, just feels to far away for most people to take action. So using calls like "Today Only" or "This Weekend Only" or "Ends Friday" or other deadlines within a 7 day timeframe are extremely effective to help your customers take action on your Etsy Shop.
You may feel like you are being manipulative by doing it. But honestly, even if a customer really really wants to buy a product from you, they still may not prioritize it (such as place an order for Mother's Day by a certain day), unless you set a deadline for them to do it.
So get into the habit of setting deadline when you sell on Etsy. You are almost certainly likely to see at least a little increase in sales.