I too have just noticed this tag.imonomy.com preload.js Javascript script program pop up on my system. I am running Firefox browser, Windows 7, I have avast free antivirus, AdBlock+, and occasionally run spybot S&D and or Malwarebytes if I feel I have an issue with something that should not be making it's way into my system such as this invasive program.
I don't care what anyone says about imonomy being a reputable entity they are trying to invade my system, attempting to install god knows what with their preload.js, which is a javascript script, which could do a lot of harm depending on the payload. I can only speak for myself, but on my system they have not been invited, not directly, nor indirectly as a third party software, the type usually delivered with free downloads, so with that said, how can anyone say they seem like a reputable entity. They have not been invited onto my system, yet they are trying to invade by sending a javascript preload in hopes that I or others would allow it to run, this in itself makes them no good in my book, and leaves this issue far from solved.