There are currently more than 650 daily deal sites in operation, each sending out at least one newsletter a day with several coupons inside.
Conservatively, there are some 30,000 deals a month for local businesses. Inevitably, some of these will turn out to be nightmares.
Lisa Wegner happened to get one of those nightmare deals - though it might've gone a lot worse.
In October 2011, the site DealFind.com offered a photography session downtown: $59 for a 90-minute professional in-studio photo shoot.
Wegner bought it, and almost immediately the thing went sideways.
For starters, she couldn't book an appointment for the shoot. She contacted the guy a total of nine times, to no avail.
Little did she know this particular photographer had been arrested on two counts of sexual assault in May. She continued to contact him, unaware of his problems with the law.
Three more charges of sexual assault and one charge of sexual exploitation were added in June. This time Wegner read about it in the newspaper. Police say women went to the studio expecting a professional in-studio photo shoot and were assaulted there.
This, even more than the normal shady deal, raises all sorts of questions about who's responsible when bum products and vouchers are sold through deal sites.
Of course it's impossible for any deal site to anticipate which merchants will be charged with sexual assault or other serious crimes.
Still, Wegner believes DealFind.com should have notified her that the business she bought a voucher for was under police investigation and should have refunded her $59.
According to the site, "If there is anything unusual about a deal (odd timing, odd location, odd condition) we make sure you know about it. Anything less would just be... odd."
Marina Glogovac, chief marketing officer at the site, assured me that every deal undergoes a screening process.
"We ran with this merchant before, and there was no public record of any known issues. Once we become aware of an issue or an allegation, we blacklist the merchant immediately."
But when Wegner was first unable to book her photo shoot, she contacted the site. She was told then that if she wanted a refund, it was between her and the studio.
Later, when she learned the photographer had been arrested, she again asked for a refund and got no answer.
After I contacted DealFind.com, the company agreed that a refund was in order (though there's no word of payment as of press time).
Wegner says she's not just angry over that. She's pressing the issue so everyone knows the extent of what can go wrong when shopping on daily deal sites.
The lesson: these sites may have changed online commerce in the past year, but buyer still beware.