Every television viewer knows the words "low ratings" are the death knell for series. It doesn't matter whether it’s a critically acclaimed sitcom about a son trying to keep his insane family together, or a beloved Western in space, low ratings mean your favorite show is not long for this world.

But increasingly, the Nielsen ratings, the most sacred numerology in Hollywood (next to Oscar ballot-counting, of course), are starting to seem out of date. That's because more and more people consume television time-shifted from its original broadcast. You most likely didn't watch the last episode of Supernatural when it actually aired. Instead, you probably viewed it on Hulu, possibly through an XBox, through a DVR device or even on your WiFi-enabled TV.

Nielsen has tracked time-shifted viewing on DVRs for some time now, but last week the company announced it will now track viewing over broadband. The Hollywood buzz is that this is a step in the right direction, but for those of us who love quirky, frequently overlooked shows, will this new tracking help save those series from getting the ax? Yes and no. First of all, Nielsen won't be able to track which shows families are viewing, just the quantity of TV content streaming over broadcast. Additionally, tracking for iPads isn't set to roll out until the end of this year.

Industry analysts have pointed out that compared to the number of people who watch on an actual television, web viewing is a drop in the bucket. According to AdWeek, non-TV views account for less than 1 percent of all total views of television content. In short, Nielsen is not going to suddenly discover that more people are watching Community than American Idol on Thursdays. And, in the short term, there won't be enough of a change in the numbers to prompt different behavior for advertisers.

In the long term, however, Nielsen is going to need to take even bigger steps to account for the way people watch TV. Remember, Nielsen ratings come from about 23,000 "Nielsen families" who are tracked throughout the year for their viewing habits. But, as the broadcast landscape becomes more and more fractured, does it make sense to compare a big reality show like Idol to a tiny niche show like Community? There is more content than ever before on screen and online -- but overall viewership, according to Nielsen, has been dropping. It may be there is more value in advertising to loyal niche viewers online than there is in trying to figure out which generically appealing show is going to get millions of families to sit on the couch on any given night.

Nielsen also doesn't account for shows that only exist online. This includes Netflix's House of Cards, but arguably should include the foreign imports from Korea and the U.K. that run on Hulu, or even popular web series that appear on YouTube (like The Guild). While these types of shows are not major players for an advertiser like Pepsi or Ford - their ratings might have value to niche advertisers, and they certainly have value to fans.

In the nearly 80 years that the Nielsen company has been tracking broadcast content, this shift to tracking internet content may be the toughest yet. Web content is an ever-shifting target, and Nielsen needs to catch up fast.