Microsoft president Steve Ballmer was caught on the back foot yesterday when Gartner Group analyst Tom Austin asked him about the "conspiracy of silence" -- a Microsoft contract clause which stops Microsoft's customers from giving out performance information about the Microsoft software they're running. "It sounds like a goofy issue to me," said Steve, and there can't be many people who'd challenge him on that. The effect -- far be it from us to say the point -- of the clause is to leave potential buyers forced to make their decisions based on Microsoft's claims. A Microsoft corporate customer would be unable, for example, to say how many clients could reasonably be run by SQL or Exchange systems. The issue is by no means confined to Microsoft, but the applause (from a hall full of corporate customers) that greeted Austin's question made it clear that the audience was all too familiar with the issue. Not so Ballmer, apparently. He said he "didn't know about legal requirements for publishing performance information". But having been convinced that the clause exists, he explained rather lamely that he expected it existed in order to stop competitors getting their hands on confidential Microsoft data, and then said he'd look into it. No doubt he'll now have to change it, whatever the corporate lawyers say -- if he doesn't, people will be asking him about it forever. Register added value MS performance factoid It has been suggested to us that Microsoft, in trying to sell Exchange to ISPs as part of an ASP solution, is fixing the number of users per Exchange server at 400. An ISP will count its users in tens, or even hundreds of thousands, of course. The 400 limit is not, claims our informant, a matter of Microsoft being determined to extract maximum sales revenue from them, but because "Exchange is just too much of a resource hog to work with more users than that". We'd like to be able to tell you our informant didn't work for S*n, but... ® Related 'Ballmer at Gartner' story MS to switch to rental model with Win2k?