In Google Instant, what does it say about sites when they appear as suggested sites?

http://en.wikipedia.org/wiki/Google_Search#Instant_Search
In Google Instant search, when you type first few letters of keyword, suggested sites will appear. For eg. when you type digitalp . the first site that is suggested is digitalpoint followed by digitalpersona
What does that say about sites like digitalpoint when it sppears as suggested site? Does it mean it is authoritative site?

 

It perhaps comes in order of what people searches when they enter those words..

 

Page rank I guess