Streaming video is a godsend if you want to catch up with recent seasons of TV series. But what's a TV fan to do who wants to stream older shows? Netflix has very little from before the millennium, and Amazon Prime has very little from before 1990.

That's not a knock; the big streaming services know their market. Still, it's worth remembering that Amazon's initial appeal as a bookseller was it's long-tail catalog, the notion that comprehensiveness was worthwhile because somebody somewhere would want that obscure or ancient title, that the markets for all those titles were collectively significant and worth catering to, and that the Internet had at last made it easier to connect those customers with what they wanted.

But until the big streaming services step into the long-tail breach, Shout Factory TV (at is ready to make a home there. The boutique streaming service, which is free and requires no subscription, launched earlier this month, brought to you by the same Shout Factory archivists who put out on DVD for the first time the old "WKRP in Cincinnati" episodes with most of the original period music (a rights-clearance nightmare that kept the episodes as originally aired off home video for decades). Alas, Shout Factory TV is a separate entity and doesn't have "WKRP" -- or much of anything else yet. But the shows that are there are, for the most part, ones that classic TV fans will want to binge on -- and that viewers unfamiliar with TV milestones should really check out.

Shout Factory's comedy section is especially vital, featuring some of the cornerstones of TV comedy as we've come to know it. Everything from "The Ernie Kovacs Collection" to "The Dick Van Dyke Show" to "The Mary Tyler Moore Show" to both of Bob Newhart's classic series to "It's Garry Shandling's Show" and "Mystery Science Theater 3000" is here.

If you're looking for a crash course on TV comedy, start with Kovacs, the 1950s innovator who experimented with the rules of television as they were being written. His let's-try-anything approach was a huge influence on David Letterman and, via Dave, on Conan O'Brien, Jimmy Kimmel, and Jimmy Fallon.

Continue with "Dick Van Dyke," which made stars out of Van Dyke and Mary Tyler Moore, and whose sharp writing about both suburban married life and television itself still hold up half a century later. Moore's own series was even more groundbreaking, both in its depiction of a divorced woman making it on her own and in its invention of the workplace-as-family sitcom. (It too offered a satirical behind-the-scenes look at television production that still holds up; TV news hasn't really improved much since dimwitted Ted Baxter was the anchor at Mary's station.) Want to see where Betty White's dirty-old-broad shtick started? This is the place.

Moore's successes included not just her own show, but also those she produced for others, including "The Bob Newhart Show" and "Newhart," both of which are streaming here. Both were sophisticated comedies about grown-ups (Bob and his TV wives in both shows had no kids). The earlier show made a star of Marcia Wallace, better known later as the voice of Mrs. Krabappel on "The Simpsons." The later show had what's generally regarded as the greatest series finale in sitcom history, an episode recently paid homage in Craig Ferguson's last "Late Late Show."

A rare find here is "Fridays," ABC's early-'80s late-night sketch comedy series, featuring the shockingly young, pre-"Seinfeld" Larry David and Michael Richards.(Also Rich Hall, Mark Blankfield, and Melanie Chartoff.) The show was a lot like "Saturday Night Live" but a lot more political and pointed. (It flourished during a period, 1980-82, when "SNL" was struggling to rebuild itself after Lorne Michaels and the original cast had departed.) It was also the site of the American TV debuts of The Clash, AC/DC, and The Stray Cats, who didn't yet have a record deal. The show wasn't on DVD until Shout Factory released a best-of collection of sketch highlights in 2013, but now you can watch full episodes at the streaming site.

Another '80s highlight is "It's Garry Shandling's Show," the highly self-referential sitcom starring the comic then best-known as a frequent guest-host on "The Tonight Show." Shandling didn't invent "breaking the fourth wall" -- that is, stepping out of character to address the audience directly, something George Burns did all the time on "Burns and Allen" back in the '50s -- but Shandling took the technique to new heights. More than any show before or since, "Shandling" deconstructed the sitcom, taking it apart to see how the rules worked before then putting it back together. Shandling would become even better known in the '90s for rewriting the rules of the sitcom with the first major single-camera, laughtrack-free success, "The Larry Sanders Show," but he learned the tricks he'd use later here.

Watching these shows is a revelation, in that the rhythms of the comedy are so different from those of today's sitcoms. One reason is that "Larry Sanders" gave rise to the cringe comedy shows of recent years, single-camera series like "The Office," "Modern Family," and "Parks & Recreation" that, instead of a laughtrack,would let each punchline be followed by an awkward pause, since the real joke is that the spoken joke wasn't really funny, and that the person uttering it was self-deluded.

The other reason is that multi-camera shows with laughtracks and some primetime cartoons (notably, "The Simpsons" and Seth MacFarlane's shows) operate at a rapid-fire pace, tossing forth a punchline every few seconds. (Don't like one? Don't worry, another will be along before you can change the channel.) One reason for the popularity of this style is the 1990s show with what may have been the fastest joke-per-minute rate ever, "Mystery Science Theater 3000." The series, streaming here, was a trailblazer of modern snark, with the three hapless "Satellite of Love" viewers maintaining their sanity by unleashing a torrent of wisecracks at the screen while being forced to watch bad sci-fi movies. In terms of the show's ability to flood the zone with insulting comments, "MST3K" may have accidentally invented the Internet.

There are some more standard, conventional sitcoms here that are plenty funny without being innovative -- the old-old-school repartee of the Abbott & Costello episodes of "The Colgate Comedy Hour," the almost creepily archetypal "Father Knows Best" (this show, the ostensible model of ideal family life on TV for decades, is why the setting of "The Simpsons" is called Springfield), the live-action "Archie" comic of "The Many Loves of Dobie Gillis" (with the Jughead character, beatnik Maynard G. Krebs, played by a pre-Gilligan Bob Denver), the slapstick high jinks of "Laverne & Shirley," and "Mary Tyler Moore" spinoff "Rhoda" (which introduced another future "Simpsons" mainstay, Julie Kavner, who went from Rhoda's needy sister to the voices of Marge Simpson and her own annoying sisters, Patty and Selma).

There are also some important dramas here -- "Hill Street Blues" (the cop drama that all modern cop dramas are drawn from), "Peter Gunn"( the late '50s private-eye series best known for its still-badass theme song), "Route 66" (the 1960s series about two adventurers on the road in a muscle car -- think of it as "Supernatural" without monsters -- which has a reboot in development), and 2000s legal drama "The Practice."

And then there's a handful of feature films -- mostly Roger Corman B-movies, a couple of Ed Wood howlers, and one unimpeachable classic (John Ford's "Stagecoach," the movie that made John Wayne a star). But none of the categories here are as strong as the TV comedy section.

Even that has its frustrations. Some -- but not all -- of the shows will play on your iOS device. Many of the series have just one season posted; this seems to be less of a rights-clearance issue than Shout Factory's way of getting you to come back later for more once additional seasons are posted.

Still, it's worth paying the site a visit. If, rather than catch up on your favorite TV comedies, you want to catch up on the shows that made those comedies possible, you would do well to spend a half-hour here, or an hour, or two, or 10...