????注意過你Facebook頁面右側那些奇怪的小廣告嗎？它們展示著難看的鞋子，或者推銷著不靠譜的成人教育學位。但是，它們一定程度上是垃圾郵件和整個在線廣告業改變的結果。

????垃圾郵件成為一門龐大的生意——當然，對互聯網用戶和網絡管理員而言也是一個大問題——因為其邊際成本幾乎為零。一旦推銷黑市偉哥或色情網站的低俗廣告制作完成，發送每封垃圾郵件的額外成本幾乎為零。發送數百萬封電子郵件比僅發送一封的成本高不了多少。因為只有極少數人會上當，所以必須大量發送，才能真正逮著愿意掏出真金白銀的用戶。

????然而，殺毒軟件制造商卡巴斯基實驗室（Kaspersky Lab）有報告稱，垃圾郵件過濾技術的發展，以及“正規”廣告費用越來越低，垃圾郵件數量正日益減少。這份報告稱：“隨著Web 2.0的出現，互聯網上的廣告機會大增：橫幅廣告、基于上下文的廣告以及社交網絡和博客上的廣告層出不窮。”

????所在行業的狀況及公司高管對行業的信心（20%）：部分公司的負責人對公司業務信心滿滿。而有些公司負責人則較為悲觀。如果你所在公司的管理團隊相信，公司能夠實現增長，那么這個信心比例是可以成立的。但如果公司管理層認為“我們玩完了”，則該信心比例將會降低。

????被認定為垃圾郵件的占總郵件的比例仍然巨大，據該報告稱在2012年為72.1％。但這一數字近年來在逐年下降，已創下五年來的新低。

????報告還稱：“正規途徑的廣告沒那么招用戶煩。”而且，由于經濟狀況的巨大變化，在很多情況下，購買橫幅廣告位的成本甚至低于發送垃圾郵件。據卡巴斯基估算，垃圾郵件的每次點擊成本（讓一位用戶點擊一個鏈接的總成本）約為4.45美元，而Facebook廣告的每次點擊成本僅為10美分。。

????所以，我們現在可以在Facebook以及其它網站上看到很多俗氣的廣告。這份報告明確指出：“傳統的垃圾郵件（例如仿制奢侈品）現在正轉戰社交網絡。我們甚至發現，某些在Facebook上做廣告的網上商店的IP地址之前是在使用垃圾郵件推廣。”。

????此外，昔日的垃圾郵件制作者還在利用團購網站Groupon等在線優惠券服務。所以，歡迎進入精彩的在線廣告世界。（財富中文網）

????譯者：項航

????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.