Note: This is not an endorsement.
Related: US cuts off 'criminal' net firm
Twitter is an opt-in communications channel. People who follow John Mayer do so because they are interested in him or his music. If they were interested in Campbell’s Soup, they would have subscribed to a Campbell’s feed (if they actually have one). The message from Campbell’s was commercial in nature and unsolicited. And that equals spam.
By hijacking a working spam network, US researchers have uncovered some of the economics of being a junk mailer...
"The best way to measure spam is to be a spammer," wrote the researchers in a paper describing their work.
Yet another reminder to "never follow links in unsolicited email messages." (and beware of intrusive/annoying ad tactics if you visit the news site's home page)