I am the kind of person who does his homework before making a purchase. I want to make sure I am getting a quality product for my money. I didn't know much about air purifiers when I first started shopping for one, but I did a lot of research, read countless reviews, and compared a variety of different brands. In the end, I decided an Alen air purifier is the only way to go! My wife and I love our BreathSmart 75i, and we are looking forward to years of service. The lifetime warranty was a big selling point for me. And although I don't anticipate having to use the warranty anytime soon, knowing that Alen stands behind their products for life gives me peace of mind knowing that I have invested in a quality product.