For companies that frequently get hit with infringement suits, fighting patent trolls is kind of like playing whack-a-mole: Beat one, and another quickly pops up to replace it. At least that’s the image that came to mind when we learned about a company called eDekka LLC, which sued 87 major retailers on Wednesday in East Texas federal court.

Since last November, eDekka has sued a whopping 150 companies with online retail businesses for allegedly infringing a single, 22-year-old patent. That’s fewer than the hundreds of companies previously sued by GeoTag Inc., another prolific patent plaintiff whose case against Google Inc. finally ran aground this week. But eDekka has only been around for six months. And like GeoTag’s assault, eDekka’s wide-ranging campaign is netting the company settlements with major defendants keen to avoid the hassle of litigation.