Nielsen/NetRatings needs you to care about audited metrics. That’s how they make their money.
I’ve just never been convinced online advertisers care about audited metrics. In more than a decade of doing online publishing, I’ve never had an advertiser ask me or one of my reps for audited traffic numbers. I’ve only heard tall tales of national advertisers asking for such numbers.
Online advertising — and maybe all advertising — is about performance. Whether you’re selling CPC or CPM-based advertising, if you can’t deliver results commensurate to your characterization of your site’s performance, you won’t retain advertisers.
The trend in online advertising is more toward performance metrics every day.
That’s why Nielsen swamping out the imprecise page view measurement for the equally imprecise time-spent metric seems so very unimportant.
For Nielsen, it’s all about revenue — their revenue, not yours.
UPDATE: BTW, how meaningful is “time spent” in the age of tabbed browsing? I might leave a tab open for hours before going back to a page and re-engaging in whatever I was doing earlier.