Been using for less than a week, and already, my Spam, which had become totally unmanageable -- 100s each day, including dozens of new ones. Got fewer than 15 all day today. Have purchased few dollars of extra fuel, happily, but don't think I really needed it, although the submissions did speed up a lot. Highly recommend using this site if you're overwhelmed by spam.
Tip for consumers: Try the free version -- give it a chance -- takes few days to kick in effectively.