My heuristic only assumes that financial incentives to get people to go to a website are so common that almost all spam does contain a link. My relay currently only filters and throttles those who are not followed by a group of paying users.
Is this spam? The URL stays the same but each client gets a different view based on when they download:
https://s3-eu-west-1.amazonaws.com/jamcams.tfl.gov.uk/00001.08859.mp4
Discussion
A happy by product of #zaps is that I know I'm dealing with someone real compared to the blue bird app when for months I didn't know whether I was posting into the wind. I understand. I could be dealing with bots, but bots that #zap 'the hardest asset in the World' are welcome.