苹果iOS移动设备（包括iPad、iPhone和iPod Touch）的用户达到了1.3亿左右，但对广告商来说，这些设备仍然存在一个巨大的盲区。所有的苹果移动设备都采用Safari浏览器，数百万台的苹果台式电脑和笔记本电脑也不例外。

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Safari一般默认关闭第三方cookies，这对保护用户隐私来说是件好事，但从广告商角度来看，这种浏览器实在很不利于追踪广告效果。

付费搜索广告管理服务公司Marin Software最近的一项调查表示，因关闭了cookie追踪功能，80%的iOS移动设备无法计算付费搜索转化率。在Mac平台上，这种无法计算的比例也达到了50%。从总体来看，在所有的浏览器中，有38%的付费搜索点击未被计算在内。

以上数据指向的是所谓的第三方cookies，并非用户所访问网站的第一方cookies。第三方cookies来自各种不同的广告网站或监测工具，它们经过不同的网站时需要重新定向。游戏邦获悉，Marin的这项调查仅针向付费搜索广告点击率，但这组数据也可以反映展示广告的相关情况。

该调查还指出，虽然广告无法在大多数苹果设备上执行有效的追踪操作，但如果可进行适当地追踪，苹果设备的广告效能会更好。游戏邦还了解到，Marin的调查将实际广告转化率与基准的Windows电脑平台转化率进行了对比，尽管从无法计算的盲区出发，该平台的预估转化率下降了56%，但实际转化率却上升了23%。

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因为无法计算的盲区不能为广告商带来收益，所以这个问题对在线广告行业构成了极大的挑战，谷歌更是深受影响。（当然，苹果可能是出于保护用户的考虑，所以采取了这种做法。）要解决这个盲区问题，开发商就得有效通过用户所访问网站的第一方cookies进行追踪，或者推出更能有效检测在线广告效能的解决方案。（本文为游戏邦/gamerboom.com编译，转载请注明来源：游戏邦）

Study: Mobile Ad-Tracking Systems Are “Blind” To 80 Percent Of Apple iOS Devices

Apple mobile iOS devices (iPads, iPhones, and iPod Touches) are used by 130 million people, but they present a huge blindspot to advertisers. All Apple mobile devices use the Safari browser, as do millions of Apple laptop and desktop computers. Safari blocks third-party cookies by default, which is good for privacy and good for consumers. But it is bad for advertisers who rely on browser cookie tracking to measure the effectiveness of their ads.

Marin Software, which offers a way to manage paid search advertising, conducted a study it provided to TechCrunch which shows that 80 percent of the time iOS devices don’t count paid-search conversions (i.e., clicks) because cookie-tracking is turned off. On the Mac, the undercounting occurs 50 percent of the time. All told, when you count all browsers, 38 percent of all paid-search clicks are not being counted.

These numbers are for so-called third-party cookies, not first-party cookies which come only from Websites you visit. Third-party cookies are served from various advertising networks or monitoring tools, and they are required for any type of retargeting across multiple Websites. While Marin only looked at paid search ad conversions, the numbers should hold true for display ads as well.

Not only are ads not being tracked properly on most Apple devices, but if they were tracked properly, Marin suggests that Apple devices actually perform better. As part of the study, Marin compared actual ad conversions to Windows computers as a baseline. While the perceived conversion rate of search ads is 56 percent lower because of the undercounting, the actual conversion rate is 23 percent higher.

Following the maxim that you don’t get paid for what can’t be measured, this blindspot poses a growing challenge to the online advertising industry, and Google in particular. (And you thought Apple was just doing this to protect consumers). The way around the blindspot is to use first-party cookies served from the Websites people visit, or to come up with better ways to measure the performance of online ads. But that’s the topic for another post. （source:techcrunch）