What is your experience with it? Did it sink your shops or you get lucky and win?
My shops experienced vast volatility during 11-14th and right after that a huge swing down. Now I'm like, at least 50% down in impressions.
All my vital keyword niches are messed up. It promoted shops that don't sell sporting goods but have a huge market in toys and junk items, it also boosted small, unknown sites that don't look professional at all.
Since 1st of January I don't see any further volatility, but I'm stuck on those lower impression levels. "Luckily," January is always a low point for me during the year and I'm hoping a small update will pass around the end of the month.
Of course - no blackhat stuff, all links are natural, nothing bad is made SEO wise. Simply a low number of external links and Google thinks you no longer need this first place and moves you to 38th position.
What is your experience with it?