There are two ways (and of course, the paths in between) you can run your startup

1 - You can go for the most popular languages: VB.NET, PHP, etc. Very easy to find people, lots of plugins, lots of support. This may be the way to go if you want something simple done in a small budget

2 - You can go for the niche languages: Haskell, Clojure, Go. that's more or less the "hipster hacker" way of doing things. Very difficult to find someone that can do even a Hello World, but once you find, they can write a scalable website in about 3 lines and connect to the newest nosql db in 2 lines more. This is good if you're the next twitter, fb, etc and your servers begin to melt even if serving login

(but then again, fb is in PHP and they added 'magic' in HipHop and infrastructure)