From Diamond's numbers for the month of April, here's how Batman Eternal did:
* 4th - BATMAN ETERNAL #1 = 96,140 copies
* 6th - BATMAN ETERNAL #2 = 76,878 copies
* 9th - BATMAN ETERNAL #3 = 72,457 copies
* 10th - BATMAN ETERNAL #4 = 70,917 copies
The only books that sold better than the first issue of Batman Eternal were AMAZING SPIDER-MAN #1; SUPERIOR SPIDER-MAN #31; and BATMAN #30.
So, overall, do people think those numbers were good or bad? It is a weekly title, so whether that dampened any interest / enthusiasm is anybody's guess. Also keep in mind those are the number of copies ordered by comic book shops; who knows how many of those were bought by readers.