I find the newsletters not only very interesting but also very practical and mostly very informative.
'Fair Exchange' was particularly very awakening. It served to remind (us) that it is not only right to reward others in terms of what they contribute, but very importantly that it rewards the giver in a psychological way ....(intrinsically the reward is beyond measure).
Sharing ideas, thoughts and opinions freely on a weekly basis opens up the opportunity for reciprocity from any of the recipients of your newsletter to engage with you in formal or informal discussion regarding the nature of services that you may provide. The reaction that you refer to by an ex-reader suggests that he or she could benefit from some coaching to assist them with their journey on earth.