Your listings recency is quite important criteria for your shop SEO. In particular, each product renewal:
improves product position in search results
improves products position on category page
makes your item to appear on your shop admirers home pages, so you get additional exposure
With Listing renewal manager you can schedule a one-time manual renewals or create an automated schedules. Within automated renewals you can select entire shop, specific categories or listings for renewal. You can also exclude any of them as well. The renewal frequency is very flexible: from once per 5 minutes to once per a week.
You can renew:
random listings
best/worst selling products
best/worst revenue products
oldest/newest items
most/least recently renewed items
listings with highest/lowest number of views/favorites
Also you can schedule renewals based on your budget, period of time or total renewals number. Renewal schedules are very flexible! It will take just a minute to create a schedule and then you don't need to worry about it anymore. The Renewal manager will renew your products based on the settings of your schedule.
Manage your renewals with Listing renewal manager by Seller Tools!
P.S.: please don't forget that Etsy charges 0.2 USD per each listing renewal.