I've been getting emails from various universities even before applying

QuantumCat
Fri, 03 Aug 2012 10:54:19 +0000

One of them reads: “You have been chosen as one of a select group of students we think would thrive at…
Students like you fit right in at …, where academic challenges open doors for the next generation of ground-breaking scientists, diplomats, computer systems engineers, or world-class business executives.”
The email address is legit. So, what does this mail imply?
Is it common for universities to contact you even before you have made a common app id?