Okay soapbox time, as someone who grew up Mormon, all missionaries are basically just nerdy 19 year old guys who want to talk about video games. I'm not kidding. Most of them are just doing what they're doing cause they don't want to disappoint their dad or whatever. Invite them in and have a good geeky chat with them, they're really nice. Also you can get them to do pretty much anything you want them to do. They'll clean your house if you ask. I'm not making this up. TLDR please be nice to them, at least for my sake.

Salespeople can get out to heck, though. I had one guy try to sell me magazines and then go "HEY YOU'RE SINGLE, WHAT DO YOU HAVE TO PAY FOR?" when I told him I didn't have the money. Asshole