The Washington Post reports that Google’s initial program to sell remnant newspaper ad inventory has been a considerable success thus far, and that it will expand the program.

This will be a key ingredient in Google’s overall plan to be a one-stop shop for advertising across many media. Bundling newspaper ad sales (along with radio, video and search) in AdSense will also help the company expand its addressable market to include businesses with traditional interest in these ad media.

Appealing to a wider audience of local and national advertisers will be a key strategy for all search engines. Yahoo! is moving in this direction with the ease of use and increased functionality of Panama, which hasn’t really had the time to prove itself yet. However, it will make itself known over the next few quarters with its traction in the marketplace.

Related: Editor and Publisher reports that The Wall Street Journal will be free in print and online on Jan. 2 in order to promote its redesign and its paid online access.