The banners appeared about a week after the site for this year's awards launched. The Feb. 24 telecast of the 80th Academy Awards could be scuttled by the writers' strike.
Until then, Oscar.com banners look to appear on the side of the home page, and across the top and on the side on other locales.
Early last week, for the first time, ABC worked out an agreement to stream the award nomination ceremonies live on Oscar.com.
While both P&G and Coke likely bought their presence on Oscar.com in concert with their on-air buys, that doesn't appear to be a requirement. A year ago, P&G had a presence on the Web site, but not in the broadcast.
The site features a compendium of photos of stars on previous year's red carpet, as well as video promos for this year's nominated films.
ABC has already begun talking with advertisers about contingency plans if the Oscar broadcast is canceled due to the ongoing writers' strike.
Interest in the Oscars does not appear to be hampered by the Writers Guild of America strike. Traffic to AOL property Moviefone's Oscar hub was up substantially Jan. 22 when nomineses were announced. The site received 10.2 million page views up from 4 million in 2007, according to an AOL spokesman.