The ability of tracking all my shipments in one place as well as being able to pay invoices online via email or text! This has been such an incredible tool with helping me manage multiple customers at once from anywhere I am working on our office computer which makes life so much easier! It would be nice if you could also track packages when they are not connected to your account but this does help keep everything organized. There was nothing really terrible about it though other then having some minor glitches here n there. Keeps everyone up date with shipment status, allows clients/customers access to information regarding their package status along with payment options available through invoice system. Shipping costs have dropped tremendously since we implemented ShipThis as our shipping provider. We were paying over $200 per month before implementing shipthis; now only around $60 monthly after saving almost 50%. In addition its allowed us to stay more updated with each customer's progress.