Early gains do not guarantee a long-term increase in search market share, and thanks to its experience with Live Search and Live Search Cashback, Microsoft (MSFT) knows this better than anyone. That said, Redmond’s new search engine, Bing, does seem to be making some solid progress.

For example, a comScore (SCOR) report said earlier this week that Microsoft’s share of the search market has risen to 11.1 percent from 9.1 percent since Bing’s debut.

And now market researcher Hitwise reports that Bing is among the top 20 most popular Web sites in the U.S. and among the top 10 in Canada (click on chart below).

“In the U.S., Bing ranked 17th among all Web sites out of over 450,000 Web sites, up from 5120 the week before the official launch when the Web site was merely a placeholder,” Heather Dougherty, Director of Research at Hitwise, wrote in a blog post. “Within the Search Engines category, Bing ranked 4th out of the search engines tracked by Hitwise…In Canada, Bing hit the top 10 among all Web sites during the first week of launch and captured 1% of all Canadian Internet visits last week. Bing also ranked 3rd last week in terms of the market share of visits within the Search Engines category behind Google Canada and Google.”

Not bad. Of course, early successes like these are driven as much by marketing as by technological prowess and positive user experience. And right now, Bing’s got some major marketing dollars behind it. But those will only last for so long.

And as Google (GOOG) CEO Eric Schmidt likes to point out, you really can’t expect to buy your way into the search market. “You don’t just buy it with ads,” Schmidt told Fox Business earlier this week. “You earn it, and you earn it customer by customer, search by search, answer by answer.”

Incidentally, June, as Todd Bishop notes over at The Seattle Post Intelligencer, happens to be the last month in Microsoft’s fiscal year, which means it’s also the end of the period in which Microsoft executive bonuses are calculated.

Dear Friends; Please do not take this for a junk letter. Bill Gates sharing his fortune. If you ignore this, You will repent later. … When you forward this email to friends, Microsoft can and will track it (If you are a Microsoft Windows user) For a two weeks time period.

For every person that you forward this email to, Microsoft will pay you $245.00. For every person that you sent it to that forwards it on, Microsoft will pay you $243.00 and for every third person that receives it, You will be paid $241.00. Within two weeks, Microsoft will contact you for your address and then send you a check.”

–Excerpt from the Microsoft giveaway hoax

My God … Bill Gates really is sharing his fortune. But not with folks who help out with that infamous Microsoft email “beta test.” He’s sharing it with consumers who use Microsoft’s Live Search engine to find and purchase products online.

Today, Microsoft (MSFT) will announce “Live Search Cashback,” a sort of search-engine loyalty program that rewards users with rebates on certain purchases of products found through Microsoft’s live.com Web search. “We want to earn your loyalty and reward it with cashback savings for your everyday online shopping,” Microsoft enthuses on the Cashback site. “We are ‘The Search That Pays You Back!’”

Cringe.

Like Microsoft’s hostile bid for Yahoo (YHOO), this new service is yet another effort to bolster its laggard search service, which has long been a very distant third in the search market. Question is, will it work? Gartner (IT) analyst Van Baker says maybe. “Assuming that the rebate amounts are enough to be appealing to people, which it sounds like they are, that definitely could attract a fair number of consumers,” Baker told the Seattle Post Intelligencer. “But what they may do is just go to that site when they’re thinking about buying something, and use Google the rest of the time.”