[JohnTHaller]

Years ago, email marketing companies schemed to use the phrase 'double opt-in' to make the process seem more onerous ('ugh, double the work is so unnecessary, right?') even though the original term was 'confirmed opt in' or 'verified opt in'. That original terminology was specifically chosen because without it, there's no way to know if the email address typed into that online form was someone legitimately signing up or not. Especially when email bombing was much more popular 15 years ago. Sadly, many folks only know the 'double' term these days. 'Double' is more commonly used today since email marketing firms do most of the talking about it. For instance, "confirmed opt in" has 92k results in Google while "double opt in" has 438k. It's much the same as the way the gambling industry rebranded themselves as the 'gaming' industry. Although in the case of 'double opt in' it's been more successful.