If a rebate is over $100, and if it's offered by a reputable company, and if I would have made the same purchase in the absence of the rebate, then I will sometimes bother to claim my rebate. I don't give much value to rebates when comparing prices; I'll take a $5 price drop over a $50 rebate.
All of which is to explain why I appreciated this post: Rebates to become more of a scam. The author has uncovered a patent application outlining advanced techniques to encourage "breakage" -- the failure of a rebate holder to get their money back. The patent deserves to fail since all of the techniques have been practiced for years, but it's nice to see them documented.
Bottom line - the only reason to bother with rebates is if you enjoy the game of getting paid.
Extra credit question: How does merging 'sick' and 'vacation' time into one time-off pool resemble a rebate scheme?