Airbnb: No place like someone else's home

— -- It's billed as a "cozy and exceptional pool cabana" with a queen bed, "amazing 5-headed shower" and a "genuinely special location where connections deepen, hearts open and peace is found."

I've booked this yoga center retreat via Airbnb.com, a 4-year-old, rapidly expanding vacation-rental service that lets socially minded travelers stay in strangers' beds — or entire homes.

The professionally staged photos? Gorgeous. The four (first-name only) reviews? Glowing. And the rate of $150 per night, not much more than what we would have paid for a room at the Motel 6 in this tony resort town? A certifiable bargain — at least until I factor in the additional $75 cleaning charge, strict cancellation policy and 12% booking fee to Airbnb.

Within minutes of our arrival at the one-acre, Spanish-style compound in a residential neighborhod about a 15-minute drive from downtown Santa Barbara, my husband and I are quaffing complimentary poolside gin and tonics with owners Jenn Houser, 42, an international business consultant, and Martin Clarke, 50, a veteran commercial airline pilot.

Granted, our cabana bed lacks a box spring, the lightbulb on a bedside table has burned out, and there's no closet or hooks for our clothes. And yes, it gives me pause when Clarke confides that the absent Airbnb host with whom I'd exchanged e-mails is actually their long-term renter — and that he, Houser and their disarmingly energetic Tibetan terrier, Tenzing, had flown in from Montana to make sure we were on the up-and-up.

The couple's tenants started listing on Airbnb this spring, and the arrangement is "still a work in progress," says Houser, who adds that she wouldn't feel comfortable without having someone on the property at the same time as a paying guest. (Airbnb says credit card payments aren't finalized until "at least 24 hours" after check-in, to make sure guests are satisfied with their accommodations and to uphold host cancellation policies.)

But what convinces me our Airbnb adventure is headed in the right direction is Clarke's response to my wistful reminiscences about In-N-Out Burger, a legendary California fast-food chain we'd frequented before moving to the East Coast. Turns out there's a branch nearby — and, as a fellow addict, he'd be happy to make a delivery run our impromptu, al fresco dinner. Motel 6, eat your heart (or "double double" with fries) out.

Listings in 19,000 cities

Founded by twentysomething, San Francisco roommates who saw their blow-up mattresses as a way to score some extra cash, Airbnb has embraced the "sharing economy" and has grown far beyond its air-bed roots.

The short-term rental service has raised $120 million in funding and now has some 200,000 active listings in 19,000 cities and 192 countries, for everything from a $10-a-night couch in Brooklyn to a $1,250-a-night, five-bedroom villa near Bariloche, Argentina. (A recent revamp focuses on photo-centric "Wish Lists" curated by fellow users and such celebs as Airbnb investor Ashton Kutcher.)

Large U.S. cities are still major markets, but fewer than a quarter of its listings are located in the USA— and 57% are for an entire apartment, home or other rental unit, which include everything from Airstreams to houseboats.

Airbnb's competition has grown, too — from other "peer-to-peer" lodging sites such as CouchSurfing.com, Roomorama.com and Wimdu.com, to the more traditional vacation rental site Homeaway.com (which also owns VRBO.com and VacationRentals.com, and limits most listings to second homes) to aggregators such as Tripping.com Dwellable.com and Rentmix.com that include multiple services. One high-end hybrid, London-based Onefinestay.com, expanded to New York City last month with "four star" homes that rent from $150 to $1,000 per night.

Fueled by a recessionary real estate slump and an increase in bargain-hunting, digitally savvy travelers looking for a more "authentic" experience, vacation rentals represented a nearly $25 billion segment of the U.S. travel market as of 2008 (the most recent figure available) and are "rocking the lodging industry," says PhoCusWright's Douglas Quinby.

But renting with or from strangers, while hardly a novel concept, requires both hosts and guests to take a financial and emotional leap of faith.

That created a massive public relations headache for Airbnb last summer, when a San Francisco woman blogged that her apartment had been ransacked and trashed by a guest who'd found her place via Airbnb.

Airbnb issued a public apology and recently expanded, to $1 million, a guarantee to help protect homeowners from theft or vandalism. The service now lets hosts see the full name of a would-be guest before they accept a booking, and phone numbers are exchanged once a reservation is finalized. Hosts and guests can call a 24-hour hotline, and Airbnb encourages guests to explain the purpose of their stay and link their account to Facebook.

Safety issues aside, the legality of short-term rentals on Airbnb and its ilk remains murky as more jurisdictions move to restrict them. Since May of 2011, a New York City ordinance bans most rentals of fewer than 30 days unless the owner lives there, though a new proposal would amend it to allow licensed properties. San Francisco officials, meanwhile, are considering legislation that would balance the city's reputation as an innovation hub with complaints from neighbors who say many under-the-radar rentals amount to ad hoc hotels.

Dubai-based Eileen Meehan, the Airbnb guest who checked into our Santa Barbara cabana after we left, says the company had cancelled her earlier Santa Monica reservation a few days before her scheduled arrival. The reason: Her host's landlord had spotted the listing online and kicked out the tenant for illegal subletting. (Airbnb found her an alternative, Meehan says, and gave her a $40 credit .)

Some gambles pay off

My own Airbnb stay, while positive, included a few hiccups.

Booking online was fairly seamless; once I'd provided travel dates and a list of candidates, the company contacted potential hosts and I received prompt yea or nay replies.

The amenity listing for our pool cabana included such items as free Wi-Fi and parking, but was vague on breakfast and kitchen facilities. (As it turned out, the owners left fruit, muffins and a pot of coffee each morning and told us we were welcome to use a refrigerator in the main house.) The check-in procedure was a bit chaotic, however, since we had to trade several e-mails and voicemails to confirm our arrival time.

But in the end, it wasn't the gratis cocktails or serenity of the courtyard koi pond that won us over. It was the chemistry with Clarke, who has invited us back for a ride in his acrobatic plane, and Houser, a self-described "trusting soul" who doesn't mind her tenants renting to Airbnb guests because she "collects houseguests" herself.

"To have a great experience, sometimes you have to take a chance," says Clarke. "Staying at a Marriott is like a bank account: low return, but your investment is safe. Airbnb is like a risky stock: Things can go wrong, but you can also win big."