Many of us have tried and used Etsy On Sale that costs us $1 per event plus $0.25 per listings (when you convert their point system to dollars and cents).
My experience is that I have sold one item that was on an Etsy On Sale event. Since I feel like I want to get the most "bang for my buck" I go for a 30 day sale. Yet, who has ever since a really successful 30 day sale? Not many.
The popular sale times are 1, 2, 3, 4, and 7 days. In the following I have omitted the 1 day sale because of the 24 hour time zone and other sales management challenges.
My suggestion is to use these sales banners on your first listing photos of only 4 listings in your shop. Also, during the sale place these 4 listings in your shop featured items. And, promote these 4 items wherever you can.
Check this out.
The Art of the Sale --- How?
The Science of the Sale --- Why?
What is the purpose or reason for having a sale?
What do you want to accomplish by having a sale?
How can you best draw attention to your sale?
Some products work well with a 2 day sale:
https://www.etsy.com/listing/157995893/2-3-4-7-day-sale-banners-instantSome products work well with a 3 day sale:
https://www.etsy.com/listing/157754010/2-3-4-7-day-sale-banners-instantSome products work well with a 4 day sale:
https://www.etsy.com/listing/157827694/2-3-4-7-day-sale-banners-instantSome products work well with a 7 day sale:
https://www.etsy.com/listing/157998645/2-3-4-7-day-sale-banners-instantAlso, Check Out the handy Sales Planner too.