PointsHound is a website that awards frequent flier miles on Aeromexico, Delta, Hawaiian, and United when using their website to make a hotel booking. They are currently offering 100 miles in any of these programs for new member sign ups via their website. The miles are in exchange for being referred by an existing member, so feel free to start a conga-line with your link in the comments section. While you’ll receive your 100 miles just for signing up, the referrer only receives points when a new member makes an actual booking. Remember, however, that most hotel loyalty programs will not award points for bookings made through third party sites, so stick to their site only if you plan on staying at a non-chain property. For those non-chain hotel bookings, you’ll earn around 4x miles for your first few nights, around 6x miles after booking 5 room nights, and around 9x miles after 20 nights. So get your free UA, DL, or HA miles just for signing up, but don’t expect additional miles as in most cases it won’t make sense for your referrals to actually book through the site.