I bought six packs of bright white bulbs and was quite disappointed to find that two of the six had problems. One flickered horribly when I first plugged it in, although after a few days of use the flickering seemed to have largely stopped. The other bulb was completely DOA. That means 33% of my purchases were bad. Based on other reviews by other people who have reviewed bright white lightbulbs, it seems that this company's quality control for bright white lightbulbs probably doesn't exist. I'll probably give this product one more chance to shine (see what I did there?) to make sure I didn't just get a bad box. However, I expect more bad pears in the next box, but we'll see how it goes.