I'm seeing very similar results at one e-commerce site that was dominating the SERPs in it's niche until the updates of Mar 23-24 and especially 30-31. They were #1 on all their high traffic / high conversion terms then got hit hard as a bunch of the terms got localized in the 23-24 update. Then there seemed to be an across the board update on 30-31 that dropped their results below a major multi-channel retailer and a major manufacturer brand. The traffic hit looks like 40-75%.
Is anyone else seeing this for pure play online e-commerce where there is strong competition from multi-channel with a strong network of traditional locations? This could be a real blow to pure play e-commerce if so.
The only other thing I see that could have impacted this site is possibly over optimized anchor text, especially to product category level pages.