The ratings were not great. Sure, Fox put it in the Friday night "death slot" but there was never a big viewing base at any point during the show. From Wikipedia :

"Firefly premiered in the U.S. on the Fox network on September 20, 2002. By mid-December, Firefly had averaged 4.7 million viewers per episode and was 98th in Nielsen ratings."



And the movie tanked. I personally LOVE Serenity, but it had a budget of $40,000,000 and made only $25,000,000 in the US.


That is not a great indicator of a massive group of Firefly fans who will support a Firefly resurrection.