There's this article from moneymanager.com.au called "Those who don't ask don't get", which talks about a survey by Wizard Home Loans shows 1 in 3 prospertive borrowers is unaware of widespread home loan discounting.
"Some of the more aggressive lenders, such as Westpac, are offering discounts of 0.7 per cent and there are reports that lenders have given their top brokers authority to discount as much as 0.9 per cent for the right business."
"you can save $68,469 on a $350,000 home loan if you cut the rate from 8.07 per cent to 7.07 per cent. On a $500,000 loan the saving is almost $100,000."
Wow, that's a lot of money, you can get get a brand new BMW for that! So if you don't ask for discounts, where does the money go? The broker's commission or back to the bank!