eBay recently came out with their 'eBay Standard Envelope' that allows sellers to ship "trackable" envelopes up to 3 ounces through the USPS.  

Link to more information from eBay https://pages.ebay.com/seller-center/shipping/ebay-standard-envelope.html

The tracking is not full tracking, but it is something and the prices are under $1 for 3 ounces.  An option like this through Shipping Easy / Stamps.com would be great for products that meet the requirements to go in an envelope, while not costing $3+ to ship them and still have some tracking on the order.

I do not think this is possible currently through Shipping Easy, I could be wrong.  If it is not, it should definitely be looked into as it can really help on small and cheap items.