[Question] How effective were vote trading schemes in the 2016 U.S. presidential election?

a.k.a. vote swapping. The idea was to pair up Clinton voters in safe blue states with third-party candidate voters in swing states. Then the Clinton voter would promise to vote for the third-party candidate in exchange for the third-party candidate voter promising to vote for Clinton.

The idea was to fight the “spoiler effect” of third-party candidates. Since a Gary Johnson voter probably doesn’t much care where their vote is cast, but a Clinton voter very much does, there’s a positive-sum trade. You could sweeten the deal by offering more Clinton voters for every third-party voter.

There was a site called TrumpTraders that did this. IIRC it was the most popular. I used another site called makeminecount.org, as a Clinton voter in MA, and was paired with a Gary Johnson voter somewhere I don’t remember.

The idea was interesting and novel. I’m curious — in retrospect, how effective were these schemes? And what problems did they run into?

My motivation is to explore if supporting a similar effort this year would be a good idea.