Teacher-Authors sometimes promise new content for a resource on a regular basis (usually monthly or quarterly), much like a magazine subscription. Teacher-Authors can market these periodical resources as a “bundle” and update the listing as new content is created and added to the original resource file. Since content will be added over time, the resource becomes a progressively growing bundle. While growing bundles can be a unique way to pre-sell your resources, there are certain responsibilities you have as a Teacher-Author. If you offer a growing bundle, here are some guidelines to follow:
- Be clear. State clearly and prominently at the beginning of your description and in your title that the resource is incomplete, and list what is currently contained in the resource file as well as what additional content will be added in the future — and when.
- Inform Buyers. In order to help educators better understand what they'll be purchasing, we suggest you include the following language at the beginning of your product description:
This is a growing bundle. Please read the product description carefully to understand which resources are included and which have not yet been added.
Here's an example: 
- Be timely. Provide Buyers with a clear timeline for when you will deliver additional content.
- Be responsive. Acknowledge Buyer questions in the event that you are unable to deliver updates when they are due.
Considering making a presale bundle? If your growing bundle doesn’t yet contain any content when you post it, please be very clear that the current file is empty and that all of the promised material is forthcoming. Also, keep in mind that until the resource contains content, it is considered an un-downloaded resource and TPT will approve refunds for Buyers who request them.
Growing or progressive bundles are a serious commitment. Buyers are counting on you to deliver these resources as promised and in a timely fashion and communicate with them along the way. If you’re unable to do so, TPT may issue refunds on your behalf on a prorated basis for missing content and your credibility as a TPT Seller may be affected.
With great bundles comes great responsibility! Think carefully about whether or not this model works for you, and use these guidelines as the rule of thumb when offering progressive bundles. Buyers will be counting on you!
For general guidelines about bundles, check out this FAQ.