Microsoft Live Expo, their experiment with classified listings that launched in early 2006, will be shut down on July 31, says a notice posted on the site. New listings have already been suspended.

This comes as Craigslist solidifies its position as the top free listings service. Other services like Kijiji (owned by eBay) and Oodle (which recently partnered with Walmart) continue to grow. Recently Kijiji has made waves about their impressive growth rate. And other classified listing startups continue to get funded.

There’s just no room for Microsoft in the classified listings space, it seems. It joins the deadpool.

A screen shot of what it looked like in the good days is below.

Walmart has added a classified listings service to their site. Silicon Valley startup Oodle, which was founded in 2004, is powering the service.

The listings are free, which means Walmart is likely doing the deal to generate page views and advertising impressions. They also now compete with both Craigslist and eBay-owned Kijiji.

Walmart has a mixed history of success with Web businesses, but Walmart.com attracts 26 million visitors a month in the.U.S., according to comScore. Amazon attracts 47 million.

The classifieds listing’s went up quietly last week on Walmart’s site. The deal should help Oodle compeet against eBay’s Kijiji, which recently passed it in in the U.S., with 2 million unique visitors in April, versus 1.3 million for Oodle. Both trail way behind Craigslist, which has 30 million uniques, and is currently embroiled in a nasty lawsuit with eBay over Kijiji’s market entry into the U.S.

Classifieds search engine Oodle has just pushed through a major upgrade to its Website, which searches 30 million active classifieds listings across the Web. It is also testing an ad network across other sites that drops a local classified from Oodle’s paid listings at the bottom of a related classifieds search on a partner site as backfill, or as a contextual ad on the side of a page.

Oodle’s new interface offers better guided search across its nine categories (cars, real estate, rentals, jobs, pets, tickets, personals, services, and items for sale). This includes the ability to refine your search in a hunt-and-peck way by selecting multiple sub-categories at once (for instance, you can look for apartments in both Williamsburg and Tribeca, or for Toyotas and BMWs, all in one search).

Depending what category you are looking in there are also lots of helpful geographical sliders and other suggested ways to parse your search (by breed, for pets; by make, price, year or mileage for cars; by neighborhood, square feet, or amenities for real estate; by gender, sexual preference, marital status, smoking habits, hair color, and zodiac sign for personals). Oodle surfaces comparative pricing information in a handy graph for categories where it has enough data, such as cars. (The average price for a used Mini Cooper in New York City, for example, is $18,132 and the 2007 models show the steepest price declines). It also gives an inventory forecast—”We found 258 listings and expect 35 more next week”—based on historical patterns. Most search results can also be seen on a Google map. .

CEO Craig Donato wants to make searching for classifieds across the Web as easy as searching for any retail product or service. But classifieds are a strange beast. He describes some of the challenges people encounter when looking for something listed as a classified:

When it is gone, it is gone—because it is one of a kind. Listings are poorly described and spread across many different sites. Searching is time-consuming. You are not just searching, you are hunting. And good deals tend to go quickly.

His approach at Oodle is to make such searches easier by adding guided categories to help people refine their searches, e-mail alerts and inventory forecasts to help people keep track of listings over time, price comparison tools to help them make a buying decision, and sophisticated spam detection to help them avoid being cheated. The search engine adds more than 500,000 listings a day from 80,000 sources, such as Autobytel, Cars.com, Career Builder, Monster.com, Kijiji, locally-tagged eBay listings, real-estate broker sites, and local newspapers.

Conspicuously absent is Craigslist, which blocked Oodle from searching its listings a couple years ago. “We have a lot more listings than Craigslist,” claims Donato. “They have massive duplication. On Craigslist, you pay with your own time to list again and again.” On Oodle, you pay if you want your listing to stand out from the crowd. “What people are paying for is visibility,” says Donato.

Oodle is creating that visibility, he says, by attracting two million visitors a month. Between 25 to 30 percent of its traffic is coming from partner sites, such as TV-station sites that want to get into the local classifieds business, as well as some regional newspapers that add local listings from Oodle’s paid inventory to their own classifieds listings (and keep the lion’s share of any resulting click-though revenues). Donato say he is in the middle of rolling out about 200 of such partner deals, and expects Oodle to turn its first operating profit next year.

Besides Craigslist, Oodle faces stiff competition from other vertical search engines that focus on classifieds, such as Edgeio, Vast, and LiveDeal. Oodle raised $11 million last March from JAFCO Ventures, Greylock Partners, and Redpoint Ventures.

Disclosure: Michael Arrington is a founder and director of Oodle competitor Edgeio.

Classified search engine Oodle got a pile of cash today, $11 million from new investor JAFCO Ventures and the leaders of their previous $5 million round, Greylock Partners and Redpoint Ventures. Like LiveDeal, Edgeio, and Vast, Oodle repackages and aggregates classified listings from around the web to make them easily searched by category, attributes, and location. Google Base also dipped its feet into this territory. Oodle’s model is taking on nearly every established vertical search by hosting listings for cars, real estate, rentals, jobs, personals, merchandise, tickets, pets, and services.

Oodle has expanded its listings through direct postings and a series of local listings partners, which it syndicates on sites like Yell.com, Local.com. include Engage.com, Local.com, ticket sellers, real estate brokers, colleges, and newspapers. However, Last year they lost their Craigslist feed. Edgeio and Vast are growing through slightly different ways. Edgeio has been partnering up with feeds from international sites, earning revenue by splitting listing fees (Edgeio marketplaces is a good example). Vast has been growing by crawling the deep web that lies behind login and search forms.

Oodle reports 20 million active listings from more than 75,000 sources in the US and the UK, when compared to Edgeio’s over 100 million international listings and Vast’s 25 million classified listings across 70,000 sites. Oodle, however, has some more advanced search features than these others, adding price tracking and maps where it makes sense. Their price tracking is a more basic version of what Mpire is offering in the shopping vertical.

Disclosure: Michael Arrington is a founder and director of Edgeio.

I wrote about this last week - and Oodle now has officially added events and tickets as a category.

This seem to be primarily a combination of meetup events and tickets from a number of ticket brokers, including stubhub. There’s lots on money in this space from affiliate fees, so it’s a smart move.

Oodle a vertical search engine for classified ads, is set to add events as a category in the next week or so. Oodle’s current categories include For Sale, Cars, Housing, Jobs and Services. With events, they will have the ability to pair revenue-generating services such as ticket sales and related items with the classifieds.

Oodle clearly needs to find new ways to generate excitement. Traffic is flattish and they recently lost the feed from Craigslist, an important source of classified ads. Oodle is all about decentralized content, a theme I constantly talk about, and I’m in their corner. I hope they find a way to make their model work.