Superb FF addon for YT Rated 5 out of 5 stars
Very useful to archive videos in a format other than FLV.
I haven't been spammed by this addon in all the time I've used it (more than a year). The only times I can remember seeing noticeable ads is when the addon is updated, as it opens a page to their Website, describing the nature of the update, and some ads related to their other products.
Giving this working, free, and frequently updated addon one star simply because they cannot tolerate even one such ad is irresponsible, rude, self-centered, not to mention ungrateful. Code your own addon if you find their mild self-promotion so offensive.