Matthew McCallum wrote:
Matthew McCallum wrote:
The whole Marvel line sold approximately 7.5 million copies per month in 1987. Leaving X-Men 1 aside (which in 1991 sold approximately 7.1 million copies itself under very unique circumstances) you are assuming some spectacular market growth for Sleepwalker to be selling 500,000 copies per issue, let alone 1 million copies per issue.  
I made a very quick search and haven't yet turned up individual sales figures per issue for 1991. However, in the Marvel Comic Group IPO published June 1991 reports monthly sales for Marvel Comics in the later half of 1990 were 8.7 million. The same documents reports in the first half of 1990 sales were 6.6 million per month. That gives us an annual average of 7.65 per month for 1990, modest growth over the 1987 tally. Such claims for Sleepwalker are unsupportable.
Okay, I did a little more digging before I have to get back to the real world:

According to reports related to Marvel's stock offering, during 1991-93, Marvel more than doubled the number of its monthly publications, both under the Marvel imprint as well as other various companies started and/or acquired, increasing to approximately 150 titles released per month. (Sleepwalker was part of this massive line expansion.)

A 1995 Advertising Age story reports that Marvel's monthly circulation (included other imprint books) dropped in 1994 to 9 million copies, a 42 percent decline from the previous year. Down the math in reverse, that means monthly circulation was approximately 15.5 million issues per month in 1993 divided across approximately 125 different titles.

Pending access to Audit Bureau of Circulation data with breakouts for each individual title, it's a relatively safe conclusion that Sleepwalker wasn't selling in the volume claimed during its 33 issue run between 1991-1994.