In the business of serving better advertising online, any technology that helps follow and track consumer behavior has value. But advertisers hoping that Flash cookies will work as an alternative to easily deleted HTTP cookies may be out of luck. 

According to a new report from analytics expert Eric Peterson, the value of Flash cookies mostly persists due to consumer ignorance. And furthermore, they might just result in more federal scrutiny of online advertising practices.

Flash cookies, or "local shared objects" (LSOs), were developed by Adobe's Flash player to track users' personal settings across different browsers and locations. But because most consumers don't know about their existence, they do not bother deleting them.

Peterson, who is CEO and principal consultant at Web Analytics Demystified, writes:

 "With the attention given to consumer privacy on the Internet at both individual and governmental levels, we believe that companies making inappropriate or irresponsible use of the Flash technology are very likely asking for trouble, (and potentially putting the rest of the online industry at risk of additional government regulation)."

Many consumers actively delete their computer's HTML cookies. Another study by Peterson released a few years ago found that 40% of consumers delete HTML cookies at least monthly.

But because Flash cookies are not stored in the same place as HTML cookies, they are not deleted when individuals clear their caches. Peterson's new report says that the cookies are “impervious” to the privacy options used by Firefox, Microsoft and Apple. While privacy settings are available in Flash, consumers don't know enough about this practice to bother changing them.

According to Peterson:

"The use of Flash LSOs is unfortunately a risky business. There is strong evidence that more and more companies are using LSOs in direct conflict with consumer preferences and existing systems designed to control access to information and protect a user’s privacy online.”

Erica Newland, a policy analyst at the watchdog group Center for Democracy & Technology, tells Mediapost:

"Right now the use of local shared objects do not align well with consumer expectations. No matter how they're implemented, we think these pose additional privacy concerns."

But that doesn't mean their usage is going away. According to researchers at UC Berkeley, 54 of the top 100 sites set Flash cookies, while 31 of them stored the same kind of information on Flash cookies as on HTTP cookies. And on those sites, user information — even if it has been deleted from their HTTP cache, can be recreated with Flash cookie information. 

While many advertisers are eager to find new ways to track consumers online, this report is more evidence that any tracking method with details that are not openly available to consumers is not likely to make it through the long haul.

The Federal Trade Commission has been on a rampage against behavioral targeting online, not because of the specific information that advertisers and publishers collect, but because of what they may be able to collect in the future. And the fact that consumers are so often in the dark about what is happening to their personal information online. According to Leonard Gordon, the Northeast director of the FTC:

"It is our belief that consumers don't really understand what they're sharing and what can be collected an d when they shop online."

Flash cookies, sadly for those looking for another route to consumer info, are not likely to be the answer.

Meghan Keane

Published 15 January, 2010 by Meghan Keane

Based in New York, Meghan Keane is US Editor of Econsultancy. You can follow her on Twitter: @keanesian.

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Comments (5)


Jim Brock

Great post. Although Flash cookies have some advantages on the surface, for the reasons you point out, those are not sustainable.

The PrivacyChoice Index notes when an ad delivery company has been seen to use Flash cookies in our user panel. We're always looking for input when people find more.

over 8 years ago

Caroline Whyatt

Caroline Whyatt, Head of Channel Experience at Royal Mail group

This article highlights some concerns I have had for a while, with a number of products using flash cookies. Great to see that others share the same viewpoint. It is amazing how many market leaders are already using them...

over 8 years ago


Rowan Heasley

Very good point Meghan and I agree it is not as easy to delete as from a browser and I too am concerned about what information sites gather on me and more particularly how they use it.

That said I am curious as to the number of people who do regularly delete or block cookies. Most people I know just couldn’t be bothered and don’t believe that the info that is collected about them will affect them in any way so I have my doubts that 40% of people delete cookies at least once a month.

Personally I only occasionally clear mine out when doing a "spring clean"

over 8 years ago

Paul Cook

Paul Cook, Director at NCC Web Performance

It's interesting to see Flash Cookies breaking into the marketing mainstream. We looked into acceptance rates last year and found that 99.9% of people who accepted flash accepted FSOs / LSOs. Clearly companies using them need to offer an opt-out and it was interesting to see that many companies have decided only to use them to restore delelted cookies so as to respect basic browser privacy settings. Some students at Berkley wrote an interesting paper last year on this subject -

over 8 years ago


Dave at UsefulArts

The Federal Trade Commission has been on a rampage against behavioral targeting online.

Making behavioral targeting and customization harder to do....setting a default assumption against it may be the wrong choice.  And it should be driven by a far wider discussion than a well meaning regulator.

The reality of the “free Internet” is that much of its content is paid for by advertisers who do so with no contractual assurance of return. Better tracking and targeting is what has kept the Internet growing while other channels are losing ad dollars.  Privacy is a good, but its mitigated by other goods.

I’m surprised to say this, but like any virtue, even Privacy requires moderation.

over 8 years ago

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