I would like to find some kind of market data detailing the sales
impact of the two voluntary nutritional food labelling programs of
which I am aware - the American Heart Association's Heartcheck
[http://www.americanheart.org/presenter.jhtml?identifier=2115], and
the Swedish Food Safety Administration's Keyhole
[http://www.slv.se/templatesSLV/SLV_Page____8190.asp].

Second-best would be sales impact data for other types of voluntary
labelling programs - eg, based on environmental, labor, or safety
standards.