I keep hearing this, but I find it goes against my own experience on the site and that of other hardcore users that I know. Food, hair, nails, tattoos, quotes, amazing pictures, unique crafts/accessories (via Etsy), aspiration products, and amazing travel pictures yes. Anything being sold by a retailer seems few and far between.
If anyone knows of anything other than anectdotal evidence that users are actually actively pinning products, I'd be really interested to read more.