Free $100 Amazon Gift Card with your first Upside.com travel / flight / hotel / uber package! Must spend min $600. Valid for all new users.
No other travel site (Expedia, Orbitz, Travelocity etc) will give you these big bonus gift cards and you won't find any better service (most websites don't really offer service anyway right?). Don't want Amazon gift cards? You can choose from many other top retailers too.