Does the Sweeps ratings period matter?

We're into the May sweeps TV ratings period, and while local stations admit that they no longer program as aggressively for such periods, you won't see them exactly allowing any of their main talent to get a vacation day during the last big viewing month of the spring and summer.
It's also the last month that fall and midseason primetime shows have original episodes. Series can only produce a couple of dozen shows per year, at best, so there aren't any left over to run past May. Summer has been taken over by reality shows, meanwhile, which is another motivator for viewers to go outside and avoid  TV altogether (exception: live sports).
The TV business is changing rapidly, like most of the media, although old habits die hard (witness the occasional 'miracle bra' or other "special report" on local stations.
The sweeps historically have been key to the setting of advertising rates, by measuring shows' audiences via Nielsen Media Research data. Increasingly the news on that front is not great for local stations, given the ascendance of the Internet and its constant challenges to attention span, not to mention the effect of DVRs and their disincentive to watch one station's programs live.
We asked savvy media expert Rich Hanley of Quinnipiac University whether he thinks sweeps still matters. He responded:
"The sweeps period seems more of a ritualistic part of the television industry than a period that yields accurate, useful and actionable data. Advertisers understand that the audience deploys DVRs and other time-shifting applications such as video Web sites that mean television programs are consumed outside the traditional prime-time window in terms of time of day and day of the month itself.
"I don't expect sweeps to go away because it is the period of measurement that all networks use and are most familiar with. But as advertising continues to leak away to content that is not related to a specific time or place, the importance of sweeps will dwindle to irrelevance. It will soon be seen as quaint as prime-time television itself."