Key findings are:

• Ronald Reagan’s 1981 inauguration drew the most viewers – almost 42 million.

• First time inaugurations of two-term presidents drew higher ratings than their second (exception: Nixon in 1973).

• The least watched inauguration since 1969: George W. Bush in 2005, with 15.5 million.

Click this link for complete inauguration ratings 1969-2005

On Sunday, Nov. 2, McCain ran just 708 TV ad units in those seven states — 48% fewer than the 1,463 ad units Obama ran that day. 

But on Monday, Nov. 3, Obama’s lead in these key battleground states shrank to 79% — or a margin of 1,510 ad units, after McCain’s campaign increased the number of TV ad units it ran in those states by 168%, to 1,900 units.

In comparison, Obama’s campaign ran 3,410 ad units in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia on Monday — a 133% increase from Sunday.

Both candidates continued to focus the bulk of their advertising on Florida, Ohio, and Pennsylvania.  On Monday, McCain ran 75% of his 1,900 ads (1,424 units) in those three states, while Obama ran 67% of his 3,410 ads (2,292 units) there.

Advertising in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia by both McCain (1,912 units) and Obama (4,119 units) peaked on Friday, Oct. 17 (6,031 combined ad units) — just two days after their final presidential debate.

In comparison, on Monday – the last day before the election – the candidates placed a combined total of 5,310 ads, falling short of their Oct. 17 combined advertising peak by 13.5%. 

For his part, McCain came within 12 ad units (6%) of his Oct. 17 advertising peak on Monday, while Obama remained 709 units (21%) shy of his highest ad unit level.

Overall, between Oct. 6 and Nov. 3, Obama placed 133% more ad units (83,903 vs. 36,070) than McCain in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia.

Nielsen’s ad unit data shows preliminary commercial occurrences and may fluctuate from day to day, as data is updated.

Read coverage of Nielsen’s findings by Bloomberg and in The Boston Globe and the Houston Chronicle.

Despite trailing Obama in terms of the total number of TV ad units placed, McCain showed a much larger percentage increase in TV advertising from the previous weekend (Friday October 24 thru Sunday, October 26) to this past weekend (Friday, October 31 thru Sunday, November 2).  

McCain bumped his TV ad units up by 76% overall in the seven battleground states Nielsen tracked, while Obama increased his advertising in those states by just 3% over the previous weekend.

Between October 6 and November 2, Obama placed 135% more ad units (80,504 vs. 34,179) than McCain in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia.

To date, both McCain and Obama have advertised most heavily in Florida.  Obama ran 24,834 ads in the state between October 6 and November 2, outpacing McCain’s 8,599 ads by almost 189%.

Nielsen’s ad unit data shows preliminary commercial occurrences and may fluctuate from day to day, as data is updated.

Stay tuned on NielsenWire for daily political ad updates from the swing states.

McCain increased his ad units by small margins in Florida, Pennsylvania, and Virginia on Thursday, Oct. 30.  He reduced the number of ad units he ran in Colorado by 1.5%, in Georgia by 31.9%, in Missouri by 1.8%, and in Ohio by 3.8%.

In comparison, Obama boosted his ad units slightly in Georgia, Missouri, Pennsylvania, and Virginia on Thursday.  Meanwhile, he reduced the number of ad units he ran in Colorado, Florida, and Ohio by small percentages.

Overall, on Thursday, McCain ran 1,814 total ad units in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia — up 2.8% from the previous day, in which he ran 1,764 ads.

Obama continues to out-advertise McCain, but he actually reduced his ad units in these states by 0.3% overall — from 3,203 units on Wednesday to 3,194 units on Thursday, Oct. 30.

On Wednesday, Obama ran 82% more ad units than McCain in these seven states, but by Thursday that lead had shrunk to 76% – or a margin of 1,380 ad units.

Between Oct. 6 and Oct. 30, Obama placed 142% more ad units (74,557 vs. 30,821) than McCain in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia.

Nielsen’s ad unit data shows preliminary commercial occurrences and may fluctuate from day to day, as data is updated.

Stay tuned on NielsenWire for daily political ad updates from the swing states.

Wednesday evening marked the release of Obama’s half-hour infomercial.

McCain increased his ad units in Colorado, Florida, Georgia, Ohio, Pennsylvania, and Virginia on Wednesday, Oct. 29.  He reduced the number of ad units he ran in Missouri by -1.7%.

In comparison, Obama increased his ad units in Florida and held his advertising steady in Georgia on Wednesday.  Meanwhile, he reduced the number of ad units he ran in Colorado, Ohio, Pennsylvania, and Virginia by slight percentages.

Overall, on Wednesday, McCain ran 1,751 total ad units in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia — up 9.4% from the previous day, in which he ran 1,600 ads.

Obama continues to out-advertise McCain, but in comparison, he boosted his ad units in these states by just 0.68%, overall – from 3,218 units on Tuesday to 3,240 units on Wednesday, Oct. 29.

On Tuesday, Obama ran 101% more ad units than McCain in these seven states, but by Wednesday that lead had shrunk to 85% — or a margin of 1,489 ad units.

Between Oct. 6 and Oct. 29, Obama placed 146% more ad units (71,400 vs. 28,994) than McCain in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia.

Nielsen’s ad unit data shows preliminary commercial occurrences and may fluctuate from day to day, as data is updated.

Stay tuned on NielsenWire for daily political ad updates from the swing states.

On Tuesday, Oct. 28, McCain ran 1,543 ad units in those seven states — up 12.9% from the previous day, in which he ran 1,366 ads.

Obama continues to out-advertise McCain, but in comparison, he boosted his ad units by just 8.7%, from 2,906 units on Monday to 3,160 units on Tuesday, Oct. 28. 

On Monday, Obama ran 113% more ad units than McCain, but by Tuesday that lead had shrunk to 105% — or a margin of 1,617 ad units.

Nielsen’s ad unit data shows preliminary commercial occurrences and may fluctuate from day to day, as data is updated.

Both candidates continue to run the bulk of their TV ads in Florida, Ohio, and Pennsylvania.  On Tuesday, McCain ran 74% of his 1,543 ads (or 1,142 units) in those three states, while Obama ran 72% of his 3,160 ads (or 2,269 units) there.

From Monday to Tuesday, both candidates increased their combined advertising by 7% in these three states.  

Overall, between Oct. 6 and Oct. 28, Obama placed 150% more ad units (68,102 vs. 27,186) than McCain in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia.

Read coverage of Nielsen’s findings by Bloomberg and in the Denver Business Journal and the Financial Times.

Stay tuned on NielsenWire for daily political ad updates from the swing states.

On Sunday, Oct. 26, McCain ran just 331 TV ad units in those seven states — 308% fewer than the 1,350 ad units Obama ran that day.  

But on Monday, Obama’s lead in these key battleground states shrank to 113% — or a margin of 1,528 ad units, after McCain’s campaign increased the number of TV ad units it ran in those states by 308%, to 1,353 units. 

In comparison, Obama’s campaign ran 2,881 ad units in Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia on Monday.

Both candidates continue to focus the bulk of their advertising on Florida, Ohio, and Pennsylvania.  On Monday, McCain ran 78% of his 1,353 ads (1,057 units) in those three states, while Obama ran 73% of his 2,881 ads (2,118 units) there.

Overall, between Oct. 6 and Oct. 27, Obama placed 153% more ad units (64,917 vs. 25,630) than McCain in these seven key battleground states.

Read coverage of Nielsen’s findings in The Wall Street Journal, the Pittsburgh Post-Gazette, The New York Times, The Boston Globe, the Los Angeles Times, and the St. Petersburg Times.

Stay tuned on NielsenWire for daily political ad updates from the swing states.

In Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia, Obama placed 155% more ad units (62,022 vs. 24,273) than McCain between October 6 and October 26, 2008.

As of October 22, Obama had placed 150% more ad units (53,049 vs. 21,106) than McCain in those key battleground states.

Obama’s advertising continues to be heaviest in Florida, where he ran 18,909 ads between October 6 and October 26, outpacing McCain’s 5,702 ads by 232%. 

In recent days, McCain has closed the gap slightly, boosting his ad units by 22% in Florida – up from 4, 662 units as of October 22.  In comparison, Obama increased his ad units in the state by just 19% between October 22 and 26.

In Ohio, where McCain’s advertising has been most prolific during the last three weeks (5,800 units), Obama ran 15,227 ad units between October 6 and October 26, besting the GOP contender by 162%.

As of October 26, both candidates continue to focus their advertising on Florida (24,611 combined ad units), Ohio (21,027 combined ad units), and Pennsylvania (16,390 combined ad units).

Meanwhile, Georgia is receiving the least amount of advertising.  McCain has placed no new ads in the state since October 17, while Obama ran just 1,468 ads there during the last three weeks.

Stay tuned on NielsenWire for daily political ad updates from the swing states.

In seven key swing states — Colorado, Florida, Georgia, Missouri, Ohio, Pennsylvania, and Virginia, Obama placed 150% more ad units (53,049 v. 21,106) than McCain between October 6 and October 22, 2008.

Obama’s advertising has been most prolific in Florida, where he ran 15,887 ads between October 6 and October 22, 2008, outpacing McCain’s 4,662 ads by 240%.

Advertising by both McCain and Obama peaked on Friday, October 17 (6,031 combined ad units) – just two days after their final presidential debate.

Both candidates have focused their advertising on Florida (20,549 combined ad units), Ohio (18,349 combined ad units), and Pennsylvania (14,286 combined ad units).

In contrast, both candidates have all but ignored Georgia, a new addition to the roster of swing states this election. Obama ran 1,410 ads in the state between October 6 and October 22, 2008, while McCain ran just 22.

Read coverage of Nielsen’s findings in The Boston Globe.

Stay tuned on NielsenWire for daily political ad updates from the swing states.

The TV audience for the senators’ third meeting edged past that of their first debate at the end of September, which drew 52.4 million viewers, but was easily surpassed by the audience of 63.2 million that tuned in for the second presidential debate last week.

During the previous presidential campaign, 51.2 million viewers tuned in for President Bush and John Kerry’s third debate on Oct. 13, 2004.  (View complete historical debate ratings.)

As was also the case in 2004 for the third debate, FOX did not carry the debate because of the Major League Baseball League Championship Series.  On Wednesday night, during the Obama-McCain debate, just over 8 million viewers tuned in on FOX to watch the Philadelphia Phillies face off against the Los Angeles Dodgers.

Coverage of the McCain-Obama debate was carried live on ABC, CBS, NBC, Univision, BBC-America, CNBC, CNN, FOX News Channel, MSNBC and MUN2, and on tape delay on Telemundo Wednesday night.

View the full media alert.

Read coverage of Nielsen’s findings by the Associated Press and Reuters, as well as in The Boston Globe, Huffington Post, Variety, Ad Age, TV Week, and Broadcasting & Cable.