Some studies on the visibility of EV sites.

OK, these are vendor studies, but they are much bigger sample sizes and under field conditions. The Tec-Ed study is an independent study we comissioned. These are the only studies I am aware of that VeriSign has commissioned. 
 
 
I don't think that the small sample size is the real problem in lab tests. Its the lab itself. I have been using computers for 25 years, I used a Mac every day at MIT. It has taken me over two weeks to get used to my MacBook Air and I am still finding things out now.
 
Nielsen's usability tests seem to me to be exactly right if your objective is to design something in order to sell it. I was in the Apple store for a total of about 30 minutes. I did not intend to buy that particular model going in (I was going to buy a more expensive model but they didn't have it in stock - thankfully).
 
But what matters for stopping Internet crime is the long term user interaction. 
 
 
http://www.verisign.com/static/040655.pdf <https://webmail.verisign.com/exchweb/bin/redir.asp?URL=http://www.verisign.com/static/040655.pdf>  
January 2007, Tec-Ed researched usage and attitudes of 384 online shoppers 

	*	Measured their responses to Web sites with and without green bars 

			*	100% of participants notice whether a site shows the green EV bar 
			*	93% of participants prefer to shop on sites that show the green bar 
			*	97% are likely to share their credit card information on sites with the green EV bar, as opposed to only 63% with non-EV sites 
			*	77% of participants report that they would hesitate to shop at a site that previously showed the green EV bar and no longer does so 

DebtHelp: 11% increase in transactions 
http://www.verisign.com/Resources/success-stories/SSL_and_VeriSign_Secured_Seal/debthelp.html <https://webmail.verisign.com/exchweb/bin/redir.asp?URL=http://www.verisign.com/Resources/success-stories/SSL_and_VeriSign_Secured_Seal/debthelp.html>  

Overstock: 8.6% decrease in abandoned shopping cart rate 
http://www.verisign.com/Resources/success-stories/SSL_and_VeriSign_Secured_Seal/overstock.html <https://webmail.verisign.com/exchweb/bin/redir.asp?URL=http://www.verisign.com/Resources/success-stories/SSL_and_VeriSign_Secured_Seal/overstock.html>  

Scribendi: 27% increase in transactions 
http://www.verisign.com/Resources/success-stories/SSL_and_VeriSign_Secured_Seal/scribendi.html <https://webmail.verisign.com/exchweb/bin/redir.asp?URL=http://www.verisign.com/Resources/success-stories/SSL_and_VeriSign_Secured_Seal/scribendi.html>