Prizes require people to use Live Search for a long time
Microsoft is boosting use of its search page by giving prizes to regular users.
Under a scheme called Search Perks users will get points for every keyword search they carry out via Live Search.
When people have accumulated enough points they will be able to redeem them for prizes such as music downloads, airmiles and books.
The program of rewards is only available in the US and there are limits to how many searches a day will be rewarded.
Those that sign up will be able to get points or "tickets" for 25 searches per day and usage will be monitored by a downloadable toolbar.
Those signing up before the registration deadline of 31 December 2008 will get a bonus of 500 tickets.
By cashing in 4950 tickets, or 178 days carrying out 25 searches, a Search Perks member could get a copy of Xbox 360 game Gears of War. Tickets can also be donated to charity.
Those who do not sign up early will be limited in which rewards they can get. The top prize, a wireless Xbox 360 controller, requires 5500 tickets or 200 days of searching.
However, there are only 197 days between 1 October when the service launched and the end of the promotion. Microsoft has said it might extend the loyalty scheme if it proves successful and will offer more ways to win tickets throughout the promotion.
The rewards program works with Version 6 or higher of Microsoft's Internet Explorer and a Windows PC. It ends in April 2009 after which members will be able to redeem their tickets.
Microsoft is limiting the promotion to the first million sign-ups.
Search Perks is one of several other initiatives Microsoft has both used to boost both use of its search page and to get more out of advertisers.
Launched in May Live Search Cashback gave money back to those that used the page to find the store where what the gadget or device they wanted was cheapest.