suggy has mentioned something like this. Maybe a longer description or customer reviews might make you an article /review /blog site, even if you only sell shoes? Imagine the stupidity of this.
Either way, something's rotten in Googleland, that much is clear. Until they figure it out perfectly, they shouldn't let theorists test their ideas on live sites, for five months straight. Especially not if what they experiment on takes away 60-95% of traffic.