When MSN adCenter began testing its sponsored search back in October, there were approximately 600 advertisers participating. This number has since grown to approximately 800, and MSN has put a hold on any newcomers for the time being.

DM News' article on adCenter highlights the outstanding conversion and ROI many advertisers are experiencing in the beta test. The most common request? Expand the program faster!

Currently, "The volume is low because MSN is testing only a small portion of ads while it continues streaming Yahoo! ads, as required by its contract with the search engine."

We are all anxious to see how long the inexpensive clicks and premier conversions will last once MSN opens its barn doors and fully engages Yahoo! and Google. Stay tuned....