If you're trying to figure out how much broadband is deployed, and how good it is, there's a threshold issue that has no one right answer. Let's say that you want to measure the number of households with (or with access to, as will be discussed) broadband at 25 Mbps or higher.
The most "honest" way to do it would be to see how many households actually have 25 Mbps connections right now.
But what if 25 Mbps is available, but lots of people choose a slower and cheaper connection instead? Then you might want to count "availability," not actual subscriptions. But this approach has flaws as well: What if the 25 Mbps price tier is absurdly overpriced? It's "available," in the same sense that a private jet is "available" to me. Also, if suddenly people do subscribe to 25 Mbps tiers, or the ISP upgrades everyone to 25 Mbps for free, that is certainly significant but should it count as progress in *infrastructure* deployment?
Also, there seems to be a big difference between, for example, new deployment of cable that is capable of 25 Mbps (actually trenching new wires), and upgrading an existing cable deployment to become capable of faster speeds through much-cheaper upgrades to electronics. Again, both are significant, just differently so. The difference between the two situations may inform how you would, for instance, direct subsidies.
Finally, there's a difference between a home that is "passed" by broadband and a home that is actually connected to a network. A "passed" home might be easy to connect, but it isn't necessarily connected; by contrast I am currently a FiOS subscriber but I also have currently-unused Comcast coax attached to my house.
There are pluses and minuses of each kind of measurement, and some are easier than others, but in lots of reporting about broadband these distinctions aren't made.