Does it matter for this purpose if there results are fairly terrible? I'd be surprised if they were so bad that the reporting off the loss of half their traffic overnight didn't at least resemble some real loss of traffic.
well i wasn't talking about this case particularly.. i was talking in general alexa isn't considered nearly a credible source of getting info about sites. The obvious reason is that most people don't use toolbar. (browsers like chrome don't even have toolbars, browser toolbars are ancient)