Usability 
Sensis is one of the many brands belonging to Australian fixed and mobile telecommunications and Internet giant Telstra (Wikipedia). The Sensis brand is used for Yellow and White pages directories both online and mobile and for an online web search engine, "The search engine for Australians". Sensis search's default behavior is to return sites, products and services of interest to Australians. This is a subtle distinction from the Australian versions of Google and Yahoo which return global results by default with Australian only results being an option.
Sensis Search is "Powered by Yahoo" so the results come from Bing as Yahoo itself is now Bing powered.