With only a couple of weeks remaining in “Downton Abbey’s” second season on PBS, a few lessons ought to be gleaned from the wave of publicity surrounding the “Masterpiece” production, including the first TV Guide cover in more than 30 years.

DowntonguideTo be clear, the show isn’t being showered in praise and heaped with media attention because the U.S. press has suddenly become enamored with British period dramas where the only Yank in the cast is Elizabeth McGovern. Nor is it because PBS has suddenly become so much better at marketing itself.

No, “Downton” has become a sensation the old-fashioned way: Based on word of mouth — people telling friends they have to watch it — and, yes, glowing reviews dating back to its maiden run a little over a year ago, which have helped make people wonder what the fuss is all about.

In short, PBS is being rewarded for putting on something that is really, really damn good — so good as to overcome whatever provincial limitations many Americans place on their entertainment diets.

The reason I point this out is because while the acclaim raining down on the program (or programme) became something of a running joke during the TV Critics Assn. tour (see CBS Entertainment Prez Nina Tassler comparing it to “Rob”), “Downton’s” performance — including its Emmy win last year over a highly deserving HBO miniseries, “Mildred Pierce” — puts the lie to the popular assumption in network circles the quality label is automatically, to borrow an old phrase, “boxoffice [or in this case, ratings] poison.”

“Downton” is simply so compelling — and I’ve seen all 10-plus hours of the current eight-part run, which, after a subpar penultimate episode, rallies at the finish — as to have trumped the obvious impediments mitigating against it becoming a ratings and media darling.

In fact, we’ve seen this pattern played out on other relatively little-seen channels, such as “Torchwood: Children of Earth” on BBC America. It’s just particularly surprising to watch it happen in the usually sleepy confines of PBS.

For those who tend to despair about U.S. culture, there ought to be something wonderfully reassuring about all this. Or as Maggie Smith’s Dowager Countess might say, “What is it about you little people that you’re so easily led to watch this thing called … television?”