Crowder's addition could mean the end of Jermaine Kearse. Kearse really underwhelmed last season, recording only 76 catches for 371 yards and one score, his worst season on record since 2013. He is a free agent. 
Crowder now joins a crowded Jets receiving corps that features Quincy Enunwa, whom the Jets signed to extension in December, Robby Anderson who was tendered, and tight end Chris Herndon. 
The Jets could still lose Anderson, who is a restricted free agent, but any team who does sign him will have to give the Jets a second round pick -- something the Jets don't have right now. 
Picking up Crowder is the second official move the Jets have made since free agency began. They signed corner Darryl Roberts as well. They also acquired offensive guard Kelechi Osemele from the Raiders for a fifth round pick. Ironically both Osemele and Crowder are coming off injury-plauged years in 2018, so both will have something to prove in 2019. 
The Crowder signing comes as rumors are swirling the Jets are on the precipice of signing former Broncos center Matt Paradis.