SEWP is a GWAC that NASA runs but that any federal agency can order IT products and some related services through, which is why most of the buying you will see on it has nothing to do with NASA. It is known across the industry for being quick and low friction compared with a fresh competition, which is exactly why agencies like using it. Like any GWAC, only companies holding a seat on it can receive its task orders, so the competition that matters most already happened when the vehicle itself was last awarded.

In a sentence

"This IT hardware purchase will be issued as a delivery order under SEWP." The agency chose speed over running its own competition, and only current SEWP contract holders were ever in the running for it.