It's impossible to argue that Eddie Johnson isn't underpaid—he makes just $156,333 a year compared to teammate Clint Dempsey's $5 million a year and around $4.5 million a year for Landon Donovan and Thierry Henry.
However, conducting salary negotiations in public is never a good idea, and Johnson has been very vocal about his feelings over the past few weeks via Twitter and his now infamous "Pay Me" goal celebration last week (video at the 1:10 mark of the attached clip).
Johnson scored 14 goals for the Sounders last year, one less than Henry and five more than Donovan. And while Johnson is not as marketable as those two, he certainly deserves more than what he currently earns, which is below the league average ($220,000) for forwards.
Still, carrying wage demands into the public view only distances players from their fans (the average worker in the U.S. earns $45,000 a year). It also creates an unneeded distraction for the Sounders, who are in the midst of making a serious run for the MLS Cup.