According to an aspect, a method for creating or improving customer preference profiles includes providing a decision coupon to a customer with two or more promotional options directed to related items selected to ascertain a purchasing preference associated with the related items through selection of one of the promotional options. The plug connector has an insulative housing and at least one conductive contact having a pair of spaced walls which converge to form a projection engageable in the plug receiving space of the receptacle contact. A first radiation reflector is designed in the form of a first hollow mirror for the reflection of a first part of the ray beam emitted from the laser source as a measuring beam into the open optical measuring path. Several dissimilar digital signature algorithms may be used to reduce vulnerability from algorithm compromise, and subsets of multiple digital signatures may be used to reduce the scope of any specific compromise.