Because I don't want to change something I know nothing about and works fine. Did you change the lights on your car with these?
Listen if people tell me they use this and it's great, I can post it, I personally don't see this as useful for too many people. There can be a deal on headlights for a 1967 corvette for $1, but I won't post it...
This probably isn't for you in that case. If you aren't the type of person who will upgrade/replace your own car parts, don't bother. I think some would benefit from it, but definitely not all. Is there a real downside to posting it?