Visa just announced the expansion of their No Signature  program. Citing its "popularity", Visa notes that: "According to a Visa Inc. survey, 69 percent of participants surveyed cited either convenience or speed as the primary reason for using their credit or debit card." Wow.
What this seems to signal is that Visa, and perhaps the other card brands, feel that they will make more money by eliminating barriers to the sale, such as the 2.2 seconds needed to sign your name, than it would lose in fraudulent transactions, considering this program is for transactions of US$25 or less. Also, it appears that people no longer know how to sign their names .
I have often heard (in low, barely audible whispers) that US consumers were too lazy to care about security, which is why the US will probably never have CHIP and PIN transactions for enhanced credit card authentication. We Americans are too darn busy to push 4 numbers on a key pad (4.3 second). This drives folks in the other parts of the world crazy as they are in love with CHIP and PIN  and, mistakenly, think that this technology eliminates all transaction risk. CHIP and PIN cards still have a mag stripe that can be scanned, and skimming is still a problem. It's a great authentication method, however, and would really help reduce some of the smaller, card-present CC frauds were we to adopt it.
Americans need more paranoia about credit card theft. We are much more likely to suffer some type of credit card fraud or be affected by a major credit card breach than a terrorist attack, but for some reason we are unwilling to punch in a few numbers to help protect ourselves.
The literal bottom line of the Visa announcement is this:
"Offering the No Signature Required program will allow hundreds of thousands more U.S. retailers, including traditionally cash-heavy merchants such as discount stores, to enjoy greater benefit from card acceptance on low dollar transactions. These benefits include the potential for faster payment, increased sales and operating efficiencies they don't get from cash and checks."
This targets smaller merchants who don't understand security. Hope it works out for them.