垃圾邮件为什么变少了

    注意过你Facebook页面右侧那些奇怪的小广告吗？它们展示着难看的鞋子，或者推销着不靠谱的成人教育学位。但是，它们一定程度上是垃圾邮件和整个在线广告业改变的结果。

    垃圾邮件成为一门庞大的生意——当然，对互联网用户和网络管理员而言也是一个大问题——因为其边际成本几乎为零。一旦推销黑市伟哥或色情网站的低俗广告制作完成，发送每封垃圾邮件的额外成本几乎为零。发送数百万封电子邮件比仅发送一封的成本高不了多少。因为只有极少数人会上当，所以必须大量发送，才能真正逮着愿意掏出真金白银的用户。

    然而，杀毒软件制造商卡巴斯基实验室（Kaspersky Lab）有报告称，垃圾邮件过滤技术的发展，以及“正规”广告费用越来越低，垃圾邮件数量正日益减少。这份报告称：“随着Web 2.0的出现，互联网上的广告机会大增：横幅广告、基于上下文的广告以及社交网络和博客上的广告层出不穷。”

    所在行业的状况及公司高管对行业的信心（20%）：部分公司的负责人对公司业务信心满满。而有些公司负责人则较为悲观。如果你所在公司的管理团队相信，公司能够实现增长，那么这个信心比例是可以成立的。但如果公司管理层认为“我们玩完了”，则该信心比例将会降低。

    被认定为垃圾邮件的占总邮件的比例仍然巨大，据该报告称在2012年为72.1％。但这一数字近年来在逐年下降，已创下五年来的新低。

    报告还称：“正规途径的广告没那么招用户烦。”而且，由于经济状况的巨大变化，在很多情况下，购买横幅广告位的成本甚至低于发送垃圾邮件。据卡巴斯基估算，垃圾邮件的每次点击成本（让一位用户点击一个链接的总成本）约为4.45美元，而Facebook广告的每次点击成本仅为10美分。。

    所以，我们现在可以在Facebook以及其它网站上看到很多俗气的广告。这份报告明确指出：“传统的垃圾邮件（例如仿制奢侈品）现在正转战社交网络。我们甚至发现，某些在Facebook上做广告的网上商店的IP地址之前是在使用垃圾邮件推广。”。

    此外，昔日的垃圾邮件制作者还在利用团购网站Groupon等在线优惠券服务。所以，欢迎进入精彩的在线广告世界。（财富中文网）

    译者：项航

    Those weird little ads on the right side of your Facebook page—the ones depicting ugly shoes or pitching iffy continuing education degrees—are partly the result of the changing economics of both spam and online advertising in general.

    Email spam became a huge business—and a huge problem for both Internet users and network managers—because marginal costs are near zero. Once a sleazy pitch for gray-market Viagra or a porn site is written, the additional cost of each spam message sent is almost nothing. Sending out millions of emails doesn't cost much more than sending out just one. Very few people fall for the usually scammy offers, so sending them in bulk is necessary to actually snag paying customers.

   But improvements to spam-blocking technologies, together with ever-cheaper "legit" advertising have worked to decrease email spam, according to a report from Kaspersky Lab, a maker of antivirus software. "With the emergence of Web 2.0," the report states, "advertising opportunities on the Internet have skyrocketed: banners, context-based advertising, and ads on social networks and blogs."

    The percentage of email identified as spam is still huge—72.1% in 2012, according to the report. But it's been dropping every year recently, and is the lowest it's been in five years.

    "Ads in legal advertising venues are not as irritating for users on the receiving end," according to the report. And the economics have shifted so much that it's actually cheaper in many cases to buy banner-ad space than to spam. Kaspersky estimates that the cost-per-click (the total cost to get one user to click on a link) is about $4.45 for spam, but only about 10 cents for a Facebook ad.

    Hence the cheesy ads you see on Facebook (FB) and elsewhere. The report explicitly states as much: The "classic spam categories (such as fake luxury goods, for example) are now switching over to social networks. We have even found some IP addresses for online stores advertising on Facebook that were previously using spam."

    Erstwhile spammers are also making use of online-coupon services such as Groupon (GRPN). Welcome to the wonderful world of online advertising.