Long Domain Names Vs Short Domain Names, Which One?

Sort, Memorable & Brandable Domain Names
You should choose Sort, Memorable & Brandable Domain Names if you are oriented toward brand building for your online business.

Long & Keyword Rich Domain Names
Otherwise you may consider a long & Keyword Rich Domain Names. This keyword rich domain names will bring some SEO advantages to your website, However I would not recommend too long with many dashes as it may dilute your website trust from visitors and Google perspective.