I think it’s important for people to know how their body works; besides that I guess they would understand why saliva can be used as a DNA sample. It can also be used to identify blood type, so maybe someone who doesn’t want to get blood drawn because they are afraid of needles can have their blood type identified that way. Isn’t this a community for information, just for information’s sake? Whether it’s useful or not it’s ultimately subjective. I can delete the post though, if it really is that redundant.