Is trading pins effective for marketing purposes?
Do lapel pins (for pin trading purposes) provide any sort of marketing benefit to the company/government partner, or is it just so that people can collect them?
Strange question which prompts the question, do you understand what marketing is?
If trading pins brings in business then it is a good idea but I highly doubt it would.
I would look at the many other effective forms of marketing like utilizing compelling sales copy on a website and marketing that website to your target market.
How to write a sales letter,effective marketing letter