Rollingstone.com

[Sorcerer386]

from what I understand "Behind the mask" sold roughly 800,000 copies in the US and 2 million woldwide and topped the UK album charts and made number 18 in the US (no doubt in the very beginning) but BTM for the most part is deemed by fans as a commercial "failure"

I think the reason why BTM was considered a commercial failure is because of the reputation Fleetwood Mac had already had. Each album went at least double platinum just in the U.S. alone, so BTM only going gold would be a failure (same reasoning of Tusk after Rumours being considered a commercial failure). When you sell a lot and then an album comes out that doesn't sell as much, it's considered a failure. But it all comes down to expectations, no sales figures. TISL was not ever expected I don't think to crack the top 20, much less debut there and stay there for three or four weeks.

By comparison "greatest hits" never charted in the top 40 but is the second biggest US seller for Fleetwood Mac with over 8 million units sold.

Actually, I'm almost positive Greatest Hits peaked at #14. I don't know if that was it's debut or not.

Now, as far as worrying about where albums chart, it's not that (at least for me) I really care where they chart. I'm not going to say, this album didn't chart well, so I don't like it. Otherwise, I'd never listen to Street Angel. It's just the excitement of seeing your favorite band, especially one that has been around as long as FM, doing well. I'm sure the members of FM have to care a little bit about where their albums chart, and so if it does well, they are happy, so I am happy. I'm happy FOR them.