I spotted the restaurant while on a stroll near my daughter's San Francisco apartment. The menu looked good, the prices were right. I decided to check its reviews online.
Then I saw the sign on the window of Bai Thong Thai: "Stop the Bully. Boycott Yelp."
Yelp is my go-to guide to the unknown. Like millions of other folks, I use the site to get the low-down on restaurants, nail salons, auto repair shops.
Bai Thong was a "3" on a 5-star scale, according to 88 Yelp reviews.
But the sign, posted by the owner, suggested the restaurant's score would be higher if Yelp hadn't manipulated rankings by hiding good reviews.
"Our customers repeatedly tell us they have submitted very good reviews" that never show up on the website. "We asked Yelp. We were told 'perhaps if you paid to do Yelp ads, we could help with this,'" the sign read.
"We earn our good reviews. We will not pay bribes to Yelp to post them."
Bai Thong has plenty of company.
Hundreds of disgruntled business owners have accused Yelp — the Goliath of crowd-sourced reviews — of tweaking its review system in order to prod low-rated companies to advertise on its site.
The claim that Yelp filters reviews to benefit its bottom line has been the subject of several lawsuits, all rejected by judges before ever reaching trial.
Yelp spokeswoman Kristen Whisenand denied that the reviews depend on whether businesses buy ads. "I don't know the exact script people use when they sell advertising," she said. "But there's no amount of money anyone can pay Yelp to manipulate reviews."
The filtering system protects consumers, she said, by screening out fake postings.
According to Whisenand, "a very sophisticated software system" decides which reviews seem real enough to count toward a business' ranking.
Apparently the system is so complicated that Yelp couldn't determine why the fellow who cuts my hair ended up with a string of negative reviews, while a batch of compliments — including mine — were considered suspect.
Yelp started up almost 10 years ago, guided by a novel concept: "Real people. Real reviews." But as its power to influence consumers grew, those real people — friends or rivals of business owners — began posting not-so-real reviews.
So Yelp developed an algorithm to spot suspected phonies and funnel them to a harder-to-access public cache. "If we didn't have this," Whisenand said, "we'd be overrun with … businesses looking to deceive consumers."
The process was intended to preserve the website's reputation. But it's also drawn back the curtain on what is beginning to look less like a consumer resource and more like a forum for savvy commentators.
The algorithm may not be, as some have claimed, part of an extortion scheme. But it does favor frequent reviewers, especially those with a following.
And it's suspicious of folks like Martie, with no photo, no profile, no followers; her first review was a 5-star paean to her favorite knitting store.
She gushed over the shop's good prices and "amazing collection" of yarns. Several other customers posted positive reviews about that same time. And just about all of them were banished to Yelp's untrusted file.
"We all knit together and we all discovered Yelp at the same time," she told me. "So my favorite store and my own reviews had been algorithmed out? And all the old negative ratings still remain on Page 1?"
At the top of the list is a review by Sandra, who has 95 followers and has written 92 other reviews. She gave the knitting store 3 stars; the owner, she said, loses points for having too much yarn and an "overbearing son."
Yelp visitors like Sandra's style. They gave a thumbs-up to her review, rating it useful, funny and cool.
I'm not looking for entertainment. I'm just trying to find a good restaurant, an honest mechanic, a hairdresser who does subtle highlights.
But Yelp, which is not yet profitable, is looking to build the kind of "community" that engages active consumers. You can write too few reviews to be considered legitimate, but apparently you can't write too many.
In fact, write enough and you might become a Yelp Elite and score invites to fancy parties.
Like Jenelle B from Pasadena. She's got 421 friends and has written 391 reviews, on everything from a Jack in the Box in Granada Hills (3 stars) to Pasadena City Hall, which has 4 stars and 31 reviews on Yelp.
I understand Yelp's need to grow its brand, and business owners' desperation to protect their livelihoods.
But the algorithm seems to me aimed less at protecting consumers than rewarding reviewer loyalty.
Even Whisenand said it's not foolproof. "We admit there are perfectly legitimate reviews that get filtered out," she said. "There's no way our system can be 100% perfect. …It has to draw the line somewhere."
She thinks it makes sense to give more credence to experienced reviewers; consumers have more confidence in those who are most prolific online. "Their content is more trustworthy," she said.
But what's made the site a draw for me is the notion that people are reacting on emotion, whether they love or hate a place.
Those people churning out opinions strike me as busy self-promoters. When a novice is moved to write a review, that business made an impact.
I don't need a stand-up routine. I don't care about a reviewer's pedigree. I just want to know if you liked the haircut, the mechanic was fair, or the pad thai tasted good.