All free Wolfram Cloud products include Wolfram Data Drop Starter.
Databins under the Wolfram Data Drop Starter plan expire in 30 days and are limited to 15 MB in size. When you are downgraded to Wolfram Data Drop Starter, all of your existing databins will expire 30 days from the date you were downgraded to the Starter plan. If a databin is larger than 15 MB, you will be able to keep all of your existing entries in your databin until it expires, however, you won’t be able to add any new entries to that databin.
Any new databins created under the Wolfram Data Drop Starter plan will expire 30 days from the date they are created.