For the first time ever, the FCC has collected data (PDF) showing real-world speeds that Americans receive from their Internet providers. And the news is pretty good! Or, perhaps, it's pretty bad!

Advocacy group Free Press blasted the results, released today. "No matter how industry tries to put a positive spin on these results, the report shows conclusively that many Americans are simply not getting what they pay for," said research director S. Derek Turner in a statement. "This study indicates Comcast, Cox, and Verizon FiOS largely perform well, but other companies like Cablevision, AT&T, MediaCom, and Frontier all fail to deliver their customers the quality of service promised.

“In every other industry, giving your customers less than what they paid for is a very serious offense. ISPs should be held to the same standard, no matter how much they try to spin their way out of it.”

Nick Feamster, a Georgia Tech professor who worked with the FCC on proper metrics, had a different take. "We found that the performance of US ISPs more consistently matches their advertised promises than the ISPs in other countries—they do a pretty good job."

As for the FCC, the agency largely stays away from subjective evaluation, though it does note that "actual download speeds are substantially closer to advertised speeds than was found in data from early 2009."

Instead, the FCC report is all about the data. And that data shows the major ISPs generally offer 80-90 percent of their advertised speeds, even during the peak hours of 7pm-11pm, with cable and fiber services actually offering higher-than-advertised speeds for much of the day.

But one ISP stood out, and not in a good way: Cablevision had absolutely atrocious download speeds, dropping to nearly 50 percent of advertised speeds during peak hours.

The FCC obtained this real-world data by contracting with a company called SamKnows, which had run similar tests for the UK government. SamKnows recruited 78,000 Internet users from across the US, then selected 9000 of them to receive a specially configured router. That router took a series of measurements during March 2011 that tested broadband speed from a user's home to a remote server across the Internet. Results were checked against ISP-installed reference points to ensure accuracy.

Not surprisingly, fiber to the home was the best-performing technology, while DSL brought up the rear, but the differences were modest, especially for upload speeds.

The data finally gives consumers a standardized way to compare Internet connection quality among ISPs, rather than limiting themselves to advertised speeds and prices. Want to compare lag between ISPs, or between service tiers? Now you can.

The report also shows that, apart from Cablevision, Internet speeds no longer fall into the toilet when everyone comes home from work in the evening. And if you are lucky enough to have Verizon's FiOS—you won't notice any difference in speeds, ever.

Verizon might be interested in suing the FCC over net neutrality rules, but it's happy enough when the agency shows FiOS in a positive light. Today's speed data "confirms that Verizon FiOS Internet customers receive blazing-fast and sustained upstream and downstream speeds even during peak usage periods," said the company in a statement.

Update: Cablevision got in touch to defend its record.

"Cablevision delivers some of the fastest Internet connections in the country, on our basic tier, two higher levels of service, and our WiFi network, and this report simply does not reflect the experience of our nearly 3 million broadband customers," said a spokesperson. "Our high-speed Internet product leads the nation in consumer adoption and has consistently won top ratings in much broader and more extensive consumer surveys conducted by J.D. Power & Associates, PC Magazine and others." Those ratings, however, cover things like "overall satisfaction" and not actual download speeds.

Update 2: The FCC has just updated the chart used at the top of this post to correct an error. The updated chart is now posted above.

Listing image by Photograph by FCC