delericho
Legend
See, here's the trick - what does "very well" actually mean?
Only WotC can define that. And, indeed, only WotC can truly know how well it actually did.
[MENTION=22424]delericho[/MENTION] mentions 14 source books. I'd point out that I've got close to that for my Scarred Lands setting. Compare to how many books you have in 3e - novels, sourcebooks, whatnot - never minding the Neverwinter Nights video game, for Forgotten Realms.
Number of supplements really can't be used as a measure of success or failure, and certainly not by itself - are the "Lord of the Rings" films a failure because there are only three of them, compared with seven "Fast & Furious" films to date?
WotC published books covering all the major topics of the setting. From here, it certainly looks like they said everything they had to say in the setting. That doesn't say 'failure' to me - it says 'completion'.
Look, I love Eberron. I do. But, I think that it's a mistake to think that Eberron is even close to the same league as Forgotten Realms.
FR is always going to be a thing apart. The question is surely not "is this as big as FR", but rather "is this worth bothering with"? After all, one wouldn't declare the "Lord of the Rings" films a failure simply because the "Fast & Furious" series have made more money!