Could it be a case of redesigning the blog template to further integrate users with the ecommerce site?
The blog design is a little more "distinct" from the ecommerce site, on purpose.
Previously it was more integrated. For example, the left hand navigation for the ecommerce categories would also display on the blog pages.
I have never been able to convert readers into buyers, even when it was more integrated. So I decided to segregate it more and use "banner ads" (basically, graphics offering a 10% discount for blog readers to buy something on our site.) Unfortunately, those don't convert either.
(One reason I segregated it was because it was easier to get links when it looked like a separate section as opposed to being integrated into the ecommerce section of the site.)