TiVo owners love their digital video recorders. And cable customers who rent DVRs -- digital video recorders that save programs to a hard drive -- also have become fans, albeit, slightly more frustrated ones given cable DVRs' propensity for glitches.

There's no question that the DVR makes watching one's favorite shows easier than recording them on a VCR. You can record on a DVR, watch at a time of your choosing (called time-shifting in industry-speak) and fast-forward through the commercials, reducing an hour show by about 15 minutes.

While this technological advance has been a blessing in the short term, in the long run, it may be a curse.

About 20 percent of American homes now contain a DVR, according to Nielsen Media Research, a ratings company. It's undeniably changing how people watch TV, and while it offers added convenience for viewers, it's depressing TV ratings.

To compensate, Nielsen started reporting not just overnight ratings but a new "live plus seven" rating that includes viewing on DVRs within seven days of a program's premiere. For the week of Oct. 1, the most recent "live plus seven" ratings available, ABC's "Grey's Anatomy" gained more than 2 million viewers, Fox's "House" added 1.78 million and CBS's "CSI" grew by 1.75 million.

For networks hurt by declining ratings, that should be good news, right? But it's not, because advertisers may assume -- logically, it seems -- that most people watching on a DVR are skipping the commercials. To advertisers, the added ratings may be meaningless.

Before the fall season started, CBS Corp. president Leslie Moonves remained bullish about the future of broadcast television in spite of DVR incursion.

"I still think five years from now most people will be watching television shows in normal time periods," he said at a CBS party near Beverly Hills, Calif., in July. "I don't think that's going to change. More and more people are changing schedules around and watching on DVRs, but the majority of people want a community experience, and that's the same. DVRs haven't killed television. The Internet's not going to kill television. TV didn't kill radio, it altered it. But I think network television is still the most powerful game in town."

Moonves pointed to the fact that 40 percent of viewers watching on DVR don't fast-forward through commercials. And CBS Corp. chief research officer David Poltrack pointed to data galore in July that suggested DVRs hurt cable more than broadcast networks. That may be a comfort to CBS, but not to fans of quality dramas on cable.

In a conference call about FX's "Damages" last week, FX president John Landgraf sounded this warning: "The DVR is putting enormous pressure on the business model that underwrites the production of all of this high-quality programming. There are going to be many, many shows, dozens and hundreds of shows in the future, that will either be canceled or will not be produced because of the DVR that otherwise would have been. That's just a fact of the future."

"Damages," which has not yet been renewed for a second season, is a heavily DVRed show: 31 percent of its viewers watch the series after it airs, according to an FX spokesman. That means 31 percent of the audience is not being exposed to advertising, which has traditionally covered the production cost of prime-time series.

Landgraf said viewers of highly serialized shows -- "Damages," "Grey's Anatomy" and "Heroes" -- are most likely to watch these shows on a DVR. But if those viewers don't count, what's a network to do? Perhaps put on more reality competitions instead.

"What seems to be holding up best in this environment is live sporting events or competition reality shows where people kind of tune into an episode, but then there's something live that gives them an answer," Landgraf said, noting that reality shows are not the FX brand. "It's a dilemma. As the business leader, I'm trying to figure out how to sustain a really magnificent program like ['Damages'], notwithstanding the fact that really a kind of show where people get voted off the island is what seems to be holding up best in the current programming environment."

Alerting viewers

Another positive technological step, with no negative side I can find, is a logical one networks should have employed a long time ago: Improved communication with viewers.

Let's face it, people who work in the communications business are often some of the worst communicators. Just ask anyone who has worked in a newsroom. But it also extends to television networks. They have Web sites, they have the ability to alert fans to news about their favorite programs, but until this season, I'm not aware of a network taking much advantage of that.

Finally, CBS created its Eye-Alert. Viewers who complain about CBS Sunday night shows starting late because of football overruns can sign up at CBS.com to receive an e-mail (or text to a cell) alert about the actual start time of Sunday's shows.

It's as simple as it is obvious. Why not extend this to offering viewers the chance to sign up for alerts about their favorite programs any night of the week? Viewers could be alerted when the show they like is pre-empted, when a new episode will air with a special guest star, if a series is moving to a new night, etc.

Granted, this would require some discretion on the part of the network -- no one wants these alerts to be too frequent and regarded as spam -- but it could be a valuable communication tool.

Fox executive vice president of strategic program planning and research Preston Beckman said it was a smart idea for CBS and could work for other networks, too.

"It works for the airlines; I don't see why it wouldn't work for us," he said at a Fox party in July. "I think, for instance, if there's a presidential press conference [in prime time], it would be useful. It's kind of a smart thing. It's something we would probably look into."

'Road' returns, 'Men' moves

ABC's "October Road" returns Nov. 22 with a one-time airing at 10 p.m. Thursday before moving to its new home, 10 p.m. Monday, on Nov. 26.

"Notes From the Underbelly" returns at 9:30 p.m. Nov. 26, following "Samantha Who?" at 9 p.m.

Beginning next week, ABC's "Men in Trees" moves to 8 p.m. Friday, switching places with "20/20," which takes the old "Trees" spot at 10 p.m. Friday.

Channel surfing

Fox has ordered a full first season of Pittsburgh-set comedy "Back to You." A total of 24 episodes, two more than the usual 22, have been ordered. ... 2002 North Allegheny Senior High School graduate Paul Shearer plays guitar in the Nashville, Tenn., band Denver and the Mile High Orchestra, which made it to the finals in last week's premiere of Fox's "The Next Great American Band" (8 tonight, WPGH). ... PBS will pre-empt today's scheduled "Mister Rogers' Neighborhood" episode (11 a.m., WQED) for an episode where the children's show host visits a fire station and discusses fire safety. The change in episodes is in response to the California wildfires, and the episode repeats at 8 a.m. Sunday on WQED.

WQED airs debate

Thursday at 8 p.m., WQED-TV will televise and simul-stream a live mayoral debate (in standard and high definition) between Pittsburgh Mayor Luke Ravenstahl and his Republican challenger, Mark DeSantis. Suggested questions for panelists Michael Bartley, Tonia Caruso and Chris Moore can be submitted at WQED.org.

Former "On Q" anchor Stacy Smith will serve as moderator of the debate, sponsored by WQED and the League of Women Voters. The debate will have a studio audience and is open to the public beginning at 7:30 p.m. as studio space allows.

TV Q&A

This week's TV Q&A responds to questions about "Medium," DVRs and FiOS TV. Read it online at post-gazette.com/tv.