Some telcos, like Hong Kong Broadband, offer customers a rebate if their bandwidth doesn't reach the speeds promised.
Unfortunately, measuring mobile broadband speeds is not so simple.
Smartone CEO Douglas Li called a press conference two days ago to attack CSL's promotion of its Express 21 HSPA mobile data package.
I confess I don't recall the ads - a failure of the ads, or me, or both, so I can't tell you what they said.
But according to Li, CSL was promising download speeds of 21Mbps and he shuttled journalists in a van around Hong Kong to show that network speeds were well short of that.
Fair enough, but it's worth noting that, although Smartone felt strongly enough to put its CEO in front of the press for an afternoon, it didn't think it warranted an actual press release.
In response to the sudden clamor, Ofta told journalists that it was launching an investigation into the case under section 7M of the Telecom Ordinance, which covers deceptive advertising.
But the issue is not new. CSL pulled the ads months ago - because the campaign was over, says a CSL staffer.
And in fact, the regulator embarked weeks ago on a "preliminary investigation" into the case, which it is required to do to see if a 7M examination is warranted.
So at the moment there is no 7M inquiry and no case to answer - an important distinction. When Ofta said a full inquiry was underway, it misspoke, and it issued a clarification last night.
The regulator has been consulting with the industry for some time, and has given interested parties another week for their advice. That's it.
It may be that CSL is gilding the lily on its mobile broadband service and if so it will pay the penalty. It's for the regulator to decide.
But it's been another tawdry week for Hong Kong's telecom sector.