Internet advertising is booming. The industry has gone from $ 9.6 billion in revenue in 2001 to $ 27 billion this year, according to Piper Jaffray, an investment bank. And it is still early days. The internet accounts for only 5% of total spending on advertising, but that figure is expected to reach at least 20% in the next few years. The single largest category within this flourishing industry, accounting for nearly half of all spending, is "pay-per-click" advertising, which is used by firms both large and small to promote their wares. The benefits of the pay-per-click approach over traditional advertising (television, radio, print and billboards are obvious. Since advertisers pay only to reach the small subset who actually respond to an advertisement, the quality of the leads generated is very high, and advertisers are prepared to pay accordingly. The price: per click varies from $ 0.10 to as much as $ 30, depending on the keyword, though the average is around $ 0.50. Google made most of its $ 6.1 billion in revenue last year from pay-per-click advertising. But as pay-per-click advertising has grown into a huge industry, concern has mounted over so-called "click fraud"--bogus clicks that do not come from genuinely interested customers. It takes two main forms. If you click repeatedly on the advertisements on your own website, or get other people or machines to do so on your behalf, you can generate a stream of bogus commissions. Click fraud can also be used by one company against another: clicking on a rival firm’s advertisements can saddle it with a huge bill. Bogus clicks are thought to account for around 10% of all click traffic, though nobody knows for sure. A few months ago Mr. Gross pioneered an alternative to the pay-per-click model. In February, Snap, a search engine backed by Mr. Gross, launched "pay-per-action" (PPA), a new model in which advertisers pay only if a click on an ad is followed by an action such as a purchase or a download. Might this put an end to click fraud Don’t bet on it, says Mike Zeman at Starcom, an advertising agency. Payper-action will be a niche, he predicts, since converting a click into an action depends on a variety of factors such as the ease of use of the advertiser’s website. Google and its peers will be reluctant to be so dependent on factors outside their control. But Mr. Tobaccowala thinks pay-per-action could become a real alternative to pay-per-click. As bigger companies spend more on internet advertising; they will demand more accountability and a wider range of options, he says. At the very least, that means clamping down on click fraud; but it also presents an opportunity for entrepreneurs to invent new models that are less vulnerable to abuse. The advertisers and the website operators have the conflict caused by ______.
A. the fraud click.
B. the ignoring of fraud-detection from website operators.
C. losing money in "pay-per-click" advertising.
D. whether the PPA model should be used.
To Journalists, three of anything makes a trend. So after three school shootings in six days, speculation about an epidemic of violence in American classrooms was inevitable, and wrong. Violence in schools has fallen by half since the mid-1990s; children are more than 100 times more likely to be murdered outside the school walls than within them. On September 27th a 53-year-old petty criminal, Duane Morrison, walked into a school in Bailey, Colorado, with two guns. He took six girls hostage, molested some of them, and killed one before committing suicide as police stormed the room. And on September 29th a boy brought two guns into his school in Cazenovia, Wisconsin. Prosecutors say that 15-year-old Eric Hainstock may have planned to kill several people. But staff acted quickly when they saw him with a shotgun, calling the police and putting the school into "lock-down". The head teacher, who confronted him in a corridor, was the only one killed. October 2nd a 32-year-old milk-truck driver, Charles Roberts, entered a one-room Amish school in Nickel Mines, Pennsylvania. He lined the girls up, tied their feet and, after an hour, shot them, killing at least five. He killed himself as police broke into the classroom. What to make of such horrors Some experts see the Colorado and Pennsylvania cases as an extreme manifestation of a culture of violence against women. Both killers appeared to have a sexual motive, and both let all the boys in the classroom go free. But it is hard to infer from such unusual examples, and one must note that violence against women is less than half what it was in 1995. Other experts see all three cases as symptomatic of a change in the way men commit suicide. Helen Smith, a forensic psychologist, told a radio audience "men are deciding to take their lives, "and they’re not going alone anymore. They’re taking people down with them." True, but not very often. Gun-control enthusiasts think school massacres show the need for tighter restrictions. It is too easy, they say, for criminals such as Mr. Morrison and juveniles such as Mr. Hainstock to obtain guns. Gun enthusiasts draw the opposite conclusion: that if more teachers carried concealed handguns, they could shoot potential child-killers before they kill. George Bush has now called for a conference on school violence. Will it unearth anything new, or valuable After the Columbine massacre in 1999, the FBI produced a report on school shooters. It concluded that it was impossible to draw up a useful profile of a potential shooter because "a great many adolescents who will never commit violent acts will show some of the behaviours on any checklist of warning signs.\ According to Helen Smith, why did the men kill others before they commit suicide
A. They want to take revenge on the society.
B. They want to vent their anger on others before they die.
C. They want companionship instead of loneliness when they die.
D. They want to satisfy their sexual desire before their death.