Republicans contend otherwise and say the ad "underscores the high stakes America faces in the global war on terror by using the words of the terrorists themselves as they describe their intention towards the United States, " according to a statement.

CNN: GOP terrorism ad sparks Democratic furor

Chang's said roughly 1 million people clicked, recirculated or otherwise interacted with the Twitter ad.

WSJ: Twitter's Mobile Ads Begin to Click

It's an ad that would otherwise only be seen by voters in a sleepy district in upstate New York.

NPR: YouTube Emerges as Political Tool in Campaigns

Others employ special software to copy the app in its entirety and swap out its automated advertising provider with one of their own choosing, allowing them to generate ad revenue that would otherwise flow to the legitimate app maker.

WSJ: Clone Wars Roil App World

Well for starters, relying upon vendor, ad network, tier 1 or otherwise, data via pixels is suicide.

FORBES: Connect

As a by-product, ad rates and ratings will be less than what they otherwise could be.

FORBES: Blatter Control: FIFA's Financially Illogical World Cup Site Selections

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

There are inappropriate executions of based on an inappropriate idea (say the car dealer ad that compared women to used cars), and there are inappropriate executions of a otherwise good idea.

FORBES: 'Got Milk?' Pulls Its PMS-Themed Campaign Amid Controversy