Page is a not externally linkable
-- Google SEO News and Discussion
---- Do outbound homepage links dilute Page Rank?
tedster - 6:04 pm on Oct 8, 2006 (gmt 0)Thread source:: http://www.webmasterworld.com/google/3112703.htm
You can put a rel="nofollow" attribute in the anchor tags for the banners. Google says they will not pass PageRank in that case.
Brought to you by WebmasterWorld: http://www.webmasterworld.com