Hi Palmtree,
The only thing I could find about blogs was after I clicked on the 'store' tab...apparently you can add one there. And there was a little more info in the FAQS
http://www.auctiva.com/free-auction-software-help/help.aspx#blog
But I don't know where it would show up...Auctiva for sure but I don't know about Ebay (Ebay has tons of info on their own blogs tho)