There's "some" truth to that advice, but I don't think the replacement schedule should be that strict. The bulb replacement schedule should be based on operating hours at the very least, not "just toss'em after 8 months". There are other variables to consider, that don't appear to be weighed with that logic. I used to replace mine when it became obvious that they weren't putting out as much light. That used to occur at around the 20 month mark for me. "Your results may vary".