SAN FRANCISCO - Google ( GOOG) is reportedly considering a push toward paid advertising, which would mark a significant departure from its long reliance on word of mouth to promote its brand. According to sources who spoke with the Wall Street Journal, the Internet giant has held discussions with several Madison Avenue advertising agencies, including Wieden + Kennedy, about new ways to boost its profile. The Journal points out that Google has already worked with Wieden + Kennedy for an advertising campaign in Japan, which included outdoor and online ads under the banner, "100 Things You Can Do with Google." Google could not be reached for comment. The company's rivals, including Yahoo! ( YHOO) and Microsoft ( MSFT), have been content to use paid advertising as a way to get their name out. But Google has prided itself in growing its empire by creating buzz among users - a sort of ground-up approach that jibes well with its "Don't Be Evil" philosophy. That approach may change though, as Google's revenue stream faces challenges in an increasingly tough economic environment. The company posted a 39% growth in revenue in its second quarter, a steep decline from the 58% growth it saw the year before. The Google brand name is now starting to show up in more places, including T-Mobile's new G1 smart phone, which supports the Android operating system created by Google. Perhaps one day it won't be so surprising to see a billboard ad featuring the smiling faces of Google founders Sergey Brin and Larry Page.