Weird, I didn't have any problems! Got the tickboxes bit and just left them blank. No spam at all. Maybe the sponsor/spam offers are US ones and don't think trying to sell anything to me in the UK is worth it!  ;-)

Daz Studio 4.8 and 4.9beta, Blender 2.78, Sketchup, Poser Pro 2014 Game Dev SR5 on Windows 8 Pro x64. Poser Display Units are inches