Do you get offers or other similar email that you really don't need to hang on to but you need for now? It isn't spam but it isn't archive worthy either. Some call it bacn.
Unfortunately, Gmail doesn't have an internal function that you can use to automatically delete your bacn. Sure, Gmail has a ton of storage but there really isn't any need to know a year from now that Newegg had a special on hard drives. Today I discovered this great blog post showing how you manage this with Google App Script.
This is a little geeky in that it is a script you have to copy, paste and modify if you like. It isn't a setting you can just flip. However, if you read carefully through the directions, you should be able to get it up and running.

Create time-based Gmail filters with Google Apps Script | johneday
Gmail users can take advantage of Google Apps Script to create time-based events that will move, mark, or label your messages without having to open a mail client.

Tech news – January 14th 2013 to January 19th 2013: