Nike continues cashing in on Kaepernick, quickly selling out of his $50 t-shirts

Social justice has turned out to be good business for Nike, as it continues to profit off its controversial partnership with former NFL quarterback Colin Kaepernick, this time with a new line of t-shirts.

Nike released the "Kaepernick Icon Tee" Thursday, a black, long sleeve t-shirt with Kaepernick's name on it, and sold out within hours at $50 each, according to The Hill.

The shirts feature the slogan "Believe in something even if it means sacrificing everything," a reference to Kaepernick allegedly being blackballed from the NFL for kneeling during the national anthem to raise awareness for social justice issues.

While Kaepernick has been out of the league since the end of the 2016 season, he doesn't appear to be hurting for cash either. Nike signed Kaepernick to an endorsement deal to be the face of it's 30th Anniversary "Just Do It" campaign, which sparked some boycotts but eventually led to all-time high share prices for the company last month.

One year ago, Kaepernick signed a book deal for $1 million with Random House imprint One World, although details of the future book have not been released.

The former quarterback still has a grievance against the NFL, claiming owners and commissioner Roger Goodell colluded to keep him out of the league because of his protests. And, he's still reportedly training and working out every day.

Still, it seems increasingly unlikely that Kaepernick will ever play another down of NFL football, as team after team continues to pass on him even in the face of severe need or injuries.

Although his name is brought up in the media whenever there's an opening on a team, it's not even clear how interested Kaepernick is in signing with a team. There have been doubts about whether he would be willing to accept a backup role and salary, but no team is likely to take the risk of signing him to be a starter after he hasn't played for more than a full season.