Improve ability to process & ship batches of orders. Either partner with ShipStation.com or innovate similar features. Some examples of useful features:
Automatically classify new orders as certain shipping type based on rules (e.g. orders from x marketplace > $y need tracking)
Generate a summary PDF of order invoice data with all relevant order info for pulling + packing (condensed so that 5+ can show per page)
Process batches of multiple orders of the same shipping type all at once, leaving behind relevant info associated with batch (pullsheet, invoices, addresses)