Today: eBay (EBAY) redesigns its user experience and expands its offerings as a booming 2012 for the San Jose company continues. Also: Personal computer sales are dropping fast, and Hewlett-Packard (HPQ) may not lead the industry anymore; Wall Street falls hard, thanks to Chevron and Alcoa.

EBay's turnaround continues with expansion of marketplace, mobile offerings

EBay's focus on the expansion of its core e-commerce model continued with a rapid-fire series of news Wednesday that included a site redesign, a new mobile app that will offer same-day delivery in the Bay Area, and a local deals offering to challenge Groupon.

The San Jose company's focus on mobile applications and offering more than just peer-to-peer auctions has helped the company's stock reach six-year highs in 2012, but CEO John Donahue's three-year turnaround plan is still producing new efforts. EBay held an event in New York City on Wednesday in which they showed off a new site design to match their new logo.

EBay's homepage will now be dubbed the "Feed," a reference to popular social-networking lingo, and is heavy on photos and the ability to compile desired objects, in a style many journalists compared with Pinterest. Users will be able to follow specific brands or types of products, and eBay will suggest similar items when they appear.

"Online shopping killed much of the pleasure of shopping ... the emotion, the excitement of discovery," eBay Chief Technology Officer Mark Carges said at Wednesday's announcement, later adding, "When you shop brick-and-mortar, you often window shop. You browse. But until now, online shopping has been about search."

EBay hopes that the redesign will translate well to mobile devices, where users usually seek to search less and click more. Donahue has been focused on mobile for years, and eBay has been able to monetize their mobile efforts very well in the past few years, helping push their revenues and stock price higher.

"We saw the mobile revolution early and we made a big bet across the entire company," Donahoe told The New York Times earlier this year. "We saw that mobile was an important factor for our customers. It was becoming the central control device in their lives. We didn't worry if it cannibalized our existing business, because we knew it was what our customers wanted."

In that vein, eBay also announced a new mobile app called eBay Now, which will allow for same-day delivery of certain items in San Francisco for now, before moving to other parts of the United States. The app, previously in beta testing and now open for general access on iOS, is a challenge to Amazon and Walmart, both of which are reportedly working on delivering online purchases on the same day.

EBay Lifestyle Deals, revealed in an exclusive report by Reuters writer Alistair Barr, is the company's answer to Groupon. While eBay is famous for offering goods to customers, Lifestyle Deals will focus more on services from local vendors -- dog-walking services and yoga classes were used as examples.

"We have a big marketplace and a lot of people who come to eBay don't just come for one thing -- they stay and buy across categories," eBay Marketplaces president Devin Wenig said Wednesday. "It makes perfect sense to experiment with new categories, and services is one of these things. We're seeing whether deals and services are attractive to our customers."

The effort uses New York startup Signpost to find local businesses looking for customers, a microcosm of efforts to lure other retailers to eBay's marketplace as an alternative to Amazon. In the larger spectrum, eBay has signed up Barnes & Noble, Toys R Us GNC and dozens of other brick-and-mortar retailers to sell on their sites.

"Sellers have to go to where the buyers are," Macquarie analyst Ben Schachter told Barr this summer, adding "(Retailers) would love to only sell through their own site, but they have to go where the buyers are, and many are on eBay."

With the new additions to their marketplace, eBay hopes to add even more customers to continue their growth. The company's earnings success has pushed its stock up 54.2 percent so far in 2012, including a 1.2 percent boost to $46.76 after Wednesday's announcements.

PC industry's woes continue, with HP's crown in question

While eBay thrives, the personal-computer industry continues to deal with weakness that has been described as "chaos." Wednesday's bad news for PC companies was a trio of reports on PC sales that indicated orders for devices could decline in 2012 for the first time in more than a decade, and Hewlett-Packard may have lost its throne as the No. 1 PC company in the world.

The first report, from IHS, predicted that 349 million PCs would sell in 2012, which would be a 1 percent decrease from 2011 sales. PC sales have not declined year-over-year since 2001, but the explosion in mobile computing has dwarfed the PC business, and companies can only hope that the introduction of Windows 8 this month can help stave off declines.

"There's less enthusiasm about PCs than there used to be," IHS analyst Craig Stice told The Wall Street Journal. "It doesn't seem that people get excited about computers nearly as much as the next iPhone or iPad."

A report on third-quarter sales from Gartner sent big waves through Silicon Valley, as the company said that Palo Alto tech giant Hewlett-Packard fell out of the top spot for PC sales in the third quarter, with China's Lenovo taking the PC throne. HP -- the world's top PC company since 2006 -- sold 13.6 million units, 15.5 percent of the market, while Lenovo sold held a 15.7 percent share at 13.8 million.

IDC, however, reported that HP sold 13.9 million for a 15.9 percent share while Lenovo sold 13.8 million for a 15.7 percent share. Obviously, HP agreed with IDC.

"The IDC analysis includes the very important workstation segment and therefore is more comprehensive. In that IDC report, HP occupies the No. 1 position in PCs," HP said in a statement.

One thing the IDC and Gartner reports did agree on -- PC sales dropped hard in the third quarter. Gartner put the decline at 8.3 percent, while IDC said 8.6 percent.

"This is definitively a crossroads" for the PC industry, IDC analyst David Daoud told the Journal. "It could be a make or break moment."

PC stocks dropped Wednesday, with HP falling 1.3 percent, Microsoft falling 1 percent, Dell sliding 1.4 percent, Intel (INTC) declining 0.6 percent, and Advanced Micro Devices dropping 3.1 percent.

Chevron helps pull Dow Jones to worst finish in months

The markets suffered in general Wednesday, as San Ramon oil giant Chevron pulled the Dow to its worst day in months after announcing Tuesday afternoon that profits would fall after a fire at its Richmond refinery.

In addition to the Chevron announcement, Alcoa's quarterly loss in the traditional kickoff to earnings season and San Jose hard-drive company OCZ's announcement of a "significant loss" cast a pall over Wall Street.

"The market is worried about what is going to happen with earnings," Randy Warren, chief investment officer of Warren Financial Service, told Reuters. "All expectations are for a softening."

Chevron declined 4.2 percent, Alcoa fell 4.6 percent, and OCZ plummeted 40.3 percent after already suffering before Wednesday's announcement. The Dow Jones industrial average dropped 1 percent, its worst day since July, while the Standard & Poor's 500 fell 0.6 percent and the tech-heavy Nasdaq declined 0.4 percent after a bad day on Tuesday.

Silicon Valley tech stocks

Up: eBay, Apple (AAPL), Tesla, Symantec, Google

Down: Yelp, Splunk, Zynga, AMD, NetApp, Facebook, Cisco (CSCO), Nvidia, Gilead, Juniper, HP, SunPower (SPWRA), LinkedIn, Electronic Arts (ERTS), Palo Alto Networks, VMware, Intel

The tech-heavy Nasdaq composite index: Down 13.24, or 0.43 percent, to 3,051.78

The blue chip Dow Jones industrial average: Down 128.56, or 0.95 percent, to 13,344.97

And the widely watched Standard & Poor's 500 index: Down 8.92, or 0.62 percent, to 1,432.56

Check in weekday afternoons for the 60-Second Business Break, a summary of news from Mercury News staff writers, the Associated Press, Bloomberg News and other wire services. Contact Jeremy C. Owens at 408-920-5876; follow him at Twitter.com/mercbizbreak.