I started commenting on a CBR forum about the alleged near-cancellation of the Batman comic book in the early 1960s, and it turned into a mini-essay on Bat-history. Hence, with some adjustments, I'm printing it here too.
There's a big problem with a lot of the out-of-context quotes we as fans encounter. I can believe someone may've told Bob Kane that DC was considering cancelling Batman, but was it someone making an accurate appraisal? Since we don't know who it was, maybe it was some DC employee trying to bring Bob Kane down a peg ("Hah, you think you're all that but your character's sales are in the toilet").
This page from the COMICS CHRONICLES demonstrates the fact that the sales weren't all that bad, and even if they were, it seems unlikely that even in '62 DC would have dumped a character with any potential for licensing. Note on the same site that WONDER WOMAN's sales are lower than either Bat-book. These days it's axiomatic that WW has often been kept around for her merchandising potential-- and Batman, unlike WW, had had two serials spun off from his comic (though I don't know how much merchandise either character generated in 1962).
I find it probable that though sales of the Bat-books weren't that good, DC editors probably focused first on discussions as to how to make them better, before anyone seriously considered dumping the titles. Such cancellation *might* have allowed Bob Kane to take the property elsewhere, depending on the terms of his contract at the time.
I don't remember if Julie Schwartz ever said that he actively campaigned for the Batman assignment or not, but I can imagine him going after it, maybe not so much because he liked the character (JS often exhibited veiled contempt for comics-characters in later years) but simply to solidify his position in the company. Previous editor Jack Schiff probably didn't care one way or another about editing Batman, though he's been quoted as claiming that the aliens and such were forced on him and that he would rather have done more Earth-style villains. Interestingly, Schwartz, who was more of a SF-guy personally than Schiff, is the one who ends up doing what Schiff wanted to do; getting rid of (most) of the aliens and concentrating on villains, often reviving characters from earlier times as Schiff had (Schiff did new versions of Mad Hatter and Clayface; Schwartz updated the Scarecrow and the Riddler).