Originally Posted by
JudderMan
In my opinion, I'd run it as a subdomain (blog.mysite.com), as it will add more weight in terms of internal linking rather than from an external site pointing at your main shop site.
Maybe try both though, create some buffer sites on WordPress for different keywords (probably your categories of whatever you're selling) and have blog posts about each item with direct links. You could hire someone to add articles to a separate WP site, as well as having your own blog on the main website. Remember though, that the external sites will need promotion in the same way, so it's more work. SEnuke X could help you out here though with the account creation.