Last year I rolled my own online shop and I included schema.org microdata for all the products. My Google ranking continued to improve during that period, but I was doing a number of improvements, so I can't say how much was due to the microdata.
My store continues to grow so I moved to an eCommerce solution. I opted to go with Volusion. Much to my surprise, about the only SEO feature they have implemented is SEO friendly URLs. They have not implemented microdata, which is pretty surprising given that all their sites are geared towards products. I would think it would be very easy for them to span the product name, description, price, etc, with a product schema.
I called CoreCommerce, a Volusion competitor, and they have not implemented microdata either.
Why are these large eCommerce providers ignoring microdata?
Are there eCommerce solutions that have implemented microdata?
Do large online retailers like Amazon and Buy use microdata?
Is there any data that shows the SEO benefits of implementing microdata for an online store?
Best,
Christopher