"Fleetwood Mac" is the main draw.
And while I agree that Stevie's absence would (and did) hurt sales, the same is true of Lindsey.
They are both considered by the "casual fans" (and even some of the more diehard fans), to be extremely essential to Fleetwood Mac.
As is Christine.
The presence of all three will almost always assure high numbers... a combination of any two of the three will also be quite successful, though not quite as huge... but if the band were down to just one (or, as has happened, none) of the three, then sales would definitely hurt.
And I believe that would be true even if that "one" happened to be Stevie. It has been speculated, and I wholeheartedly agree, that a Fleetwood Mac tour with only Stevie, would most likely sell only slightly better than one of her solo tours.
So while she sells to a respectable amount of people as a solo act, she doesn't acheive the numbers Fleetwood Mac can and does with Lindsey and/or Christine also present.
