Interesting to find out that Green Lantern Mosaic wasn't even cancelled for sales reasons or lack of support from fans. Somebody (unknown) high up in DC simply didn't like the book according to Mosaic artist Cully Hamner. Thus perpetuating a lie that books with black leads didn't sell. Based on the health of his sales, John Stewart could probably have carried a run over 100 issues. Damn shame someone powerful felt the need to end the title: Here's what Hamner said:
"(A)s I was told at the time, it didnt fit with DC editorial vision (whatever that means). Sales didnt matter, fan support didnt matter; the first issue sold about 210,000 copies and my last issue sold about 70,000, so there was plenty of support for the book. It was marked for cancellation when issue #5 came out, and they allowed Gerry Jones a year to wrap it up, but there was no doubt that it was being cancelled because somebody upstairs just didnt care for it. So, I had a feeling after a while of creatively being against a brick wall, and got out before the end. You pay your money, you takes your chances. Thats the biz"
John has always been able to carry a book solo. It just seems like editorial powers that be at DC have not neccesarily wanted his character to have as much prominence. Got worse when Geoff Johns decided Hal was the Mary Sue of Green Lanterns.