Microsoft Wednesday launched a rewards program to entice consumers to its Live Search site that requires Internet Explorer, and bars users of rival browsers including Firefox, Safari, Opera and Chrome.

A toolbar required for participation also collects some search behavior data, including the number of searches on rival engines, and transmits the information to Microsoft daily.

One search expert questioned the restriction to IE, as well as Microsoft's decision to gather a wide-ranging amount of data from users, though he refused to call the company's newest attempt to get users to try its search site as "desperate."

"Why take this approach?" asked Danny Sullivan, editor-in-chief of the Search Engine Land Web site. "I think that Microsoft would do better if they pretended they didn't own IE. But paying people to try [Live Search] doesn't mean that they're desperate. I think it's an interesting way to get people to break the Google habit."

Google, in fact, paid site owners pennies per search as far back as 1999, Sullivan said. "And no one called Google desperate then."

Dubbed, "SearchPerks," the program awards users up to 25 "tickets" a day for each completed search at Microsoft's Live Search. Then tickets can be redeemed for prizes after the program ends next April. Among the rewards Microsoft touted on the SeachPerks site: free music downloads, clothing, and frequent flyer miles on American Airlines, Delta and US Airways.

The program, which is available to US residents 13 and older who have a Windows Live ID, also requires users to download and install a small toolbar, "Perk Counter" that keeps track of the number of Live Search searches, and thus the number of reward tickets.

Perk Counter will only install in Internet Explorer, Microsoft's own browser. Competitors, including Mozilla's Firefox, Apple's Safari, Google's Chrome and Opera Software ASA's Opera, cannot be used with the SearchPerks reward program. Attempts to visit the program's Web site with any of those browsers, in fact, are greeted with the message: " To earn value for your searches and join the SearchPerks! promotion you must have Internet Explorer 6.0 or higher to participate."

According to Microsoft, the Perk Counter tallies more than the number of Live Search searches. In the terms and conditions for the program, as well as in a separate FAQ, Microsoft spelled out what the counter records and sends to its servers daily.

"The software records and sends to Microsoft the number of Web searches you do each day on different search engines; the types of searches you complete, such as for news or images; and the number of online ads you click on," states the SearchPerks' terms and conditions.

Microsoft did not specify which search engines the counter tracks.

Also transmitted are the user's IP address, the version of IE, and other data, including, "information about the browser you are using as well as which search toolbars, if any, are installed on the computer."

Microsoft said that the counter does not record a user's search terms, the results received or the content of the ads that are clicked.

Last month, Google came under fire for its practice of recording all search terms and URLs typed into the address bar of its new Chrome browser; in response, the California company, which owns the bulk of the search market share, said it would render anonymous that data within 24 hours.

"I don't think the counter needs to be tracking banner ads clicks or the search activities on other search engines," said Sullivan. "That seems to be beyond the stated goal of the program But I can understand that they want to know how people are using other search engines."

SearchPerks is not the first rewards program Microsoft has debuted to boost traffic at Live Search. In May, for example, it launched Cashback, a comparative shopping feature that gave consumers rebates on purchases made through the site.

"This is better than Cashback," said Sullivan, calling the latter "really difficult to use."

Even so, he wasn't optimistic that SearchPerks would turn around Microsoft's dismal search numbers. In August, Microsoft's share of the US search market dropped 0.6 percentage points from the month before to 8.3 percent, as Google's climbed by 1.1 points to 63 percent.

"I don't think this will be a massive game changer," said Sullivan. "But all the stuff they've tried hasn't been doing any good, so they have to try other ways. This is a valid attempt."