Last month I wrote a piece on some of the historic challenges of media measurement and how it impacts marketing. I was intrigued to write a follow up when Nielsen announced yesterday that they’d be tracking and sharing Netflix viewership data, with Amazon and Hulu purportedly to follow.For those who don’t breathe this stuff: to this point the SVOD services have not been required — and as a result have not — revealed audience data like the traditional TV networks. There are several reasons why, but at the core is their different business models. Netflix and other like services are tasked with acquiring and keeping paid subscribers, and that can most effectively be done by offering a wide variety of appealing content for multiple segments. In this context a show is not necessarily defined a “success” purely by its total ratings.On the other hand traditional networks sell advertising within their programming and these ratings directly affect how much they can charge brands. This inability to access SVOD viewership information has been to the chagrin of many industry executives: they are often seeking the viewership data of their shows to gauge success (and comparing them to the ratings of their SVOD competitors) which in turn can inform subsequent decisions on programming as well as ad rates.So is it time to cheer, and say…finally? Are the SVOD platforms softening as studios and production entities relentlessly complain about the lack of data transparency?I am not ready to believe we have found a solution, and am not even sure it is a step in the right direction. First, Nielsen will be providing the data to the clients of their new service but will not be making the numbers public (unlike their ad-based audience research). This is likely in part a hedge on its initial accuracy and in part an attempt to woo more clients.Second, and my biggest issue, is the accuracy of the data.While the methodology is not very clear (see below), we do know the audience will only be drawn from US subscribers who, per the most recent Netflix earnings, comprised about half of their total sub base. Further, viewership will be measured based on those who use a TV set only; mobile insights company App Annie recently noted there were 70M monthly active mobile Netflix users in the US (yes, that exceeds the total number of US subs, but note every account can have multiple users and that App Annie is counting individual users not individual accounts).Point here is simply this: lots of people access Netflix via mobile — and other non-TV means like laptops and desktops — so some key viewer data will be missing.Third, little was revealed about Nielsen’s methodology within this limited subset of Netflix TV viewers. In their announcement they referred to the use of “proprietary audio recognition software” in their measurement homes, but how it works is still a mystery. For the public to become truly comfortable with this type of innovation from a long-standing traditional market research firm there needs to be more detail, and there is certainly irony in an announcement touting new transparency while not fully providing it.Fourth and finally, Nielsen’s press release was conspicuously lacking a corresponding statement from Netflix. This could be construed as no big deal — Netflix is just letting Nielsen get the credit since the fruits are from their hard work — but it could also be an indication that Netflix doesn’t support it.Some may feel more optimistic, and point to this being a step in the right direction with more progress inevitably to follow. And as a media executive I completely understand the need for additional optics in order to support decision making. Furthermore a common SVOD ratings standard will for the first time provide a certain competitive framework among those that subscribe.However Nielsen’s SVOD data is going to be limited, if not flawed, and thus potentially very dangerous. In this connected world, third-party sources will have limits to the veracity of the data they can collect.Thus the media industry must persevere in collaborating with Netflix and the whole SVOD ecosystem to strive for agreed upon measurement practices, in order to garner the information they need to make the most accurate decisions for their businesses. Further, if they are not comfortable operating in the SVOD status quo, they should be able to make sacrifices for the good of their brand like several large media companies have already started to do.Whatever they use to make their choices, it should never be misinformation.