We estimate TripAdvisor to derive over 91% of its value from its advertising division.

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"I think it's clear there's no congressional appetite for even government-proposed voluntary guidelines, much less regulation, " said Mary Engle, head of the FTC's advertising practices division.

WSJ: Child's Play: Food Makers Hook Kids on Mobile Games

Media services firm MagnaGlobal, a division of advertising and marketing giant Interpublic Group (NYSE: IPG), recently lowered its 2012 forecast for total ad spending growth to 2.9 percent from 4.8 percent, pointing to a slowdown in manufacturing, consumer spending and ongoing problems in the labor and housing markets.

FORBES: Ad, PR agencies grow despite slowing U.S. ad spending growth

Meanwhile, DMGT added that at its regional newspaper division, Northcliffe, sales remained strong while advertising had grown 6%.

BBC: NEWS | Business | Daily Mail sees profits improve

We had a pretty good idea what Google and its AdMob division would think of Apple's new rules on outside advertising companies collecting analytics, but AdMob CEO Omar Hamoui has now spelled it out himself.

ENGADGET: AdMob CEO responds to Apple's new advertising rules: 'not in the best interests of users or developers' (update: Greystripe responds)

However, while the proceeds from advertising on the CBS Interactive Audience Network will be split between CBS and its partners, details of the division in funds is not yet known.

BBC: NEWS | Business | CBS to launch online TV network

AOL, at that time a division of Time-Warner, created fraudulent round-trip transactions to fund its own online advertising revenue by giving ad buyers the funds to pay for advertising they would not have otherwise purchased.

FORBES: Zynga and Facebook: A Close Relationship Can Distort Revenue