One nice thing for BAMM is that no matter what your searching walmart.com you get the results for the category your searching as well as the product (entire site). This makes books come up for almost anything you search for. Search on "GOLF" gets golf balls as well as books about golf. This can only help generate additional sales. Try it you'll see.
There is more logic behind a Border's buyout of BAMM to compete with BNBN and AMZN then Walmart buying BAMM. The recent news of MSFT & BNBN significantly distanced the 1st and 2nd place booksellers, namely BNBN and Borders respectively. I think Borders would try to expand into the traditional brik and mortal stores of the South rather than looking for a partner in some wako electronic book scheme which will probably take about ten years to get to and personally the electronic book is only good for news and mags. By merging with BAMM, Borders expands into the etailing business by consolidating the BAMM and Borders site, increasing sales by continuing the BAMM distribution agreement, and more importantly as anayst have begun to realize that you need a brick and mortal store plus a website to succeed in etailing. The continuous growth and expansion of BAMM only makes the merger attractive and the bid price higher. Consolidation is the trend of the etailing business see EGGS/ONSL merger.