On the set of "Mad Men" (AMC)

After 18 months of waiting, an average of 3.5 million people tuned in to watch Sunday’s “Mad Men” fifth season debut.

That’s a series best for the show – and about 600,000 more people than had watched the fourth season debut back in July of 2010. “Mad Men” had been off the air since October of 2010, following the fourth-season finale, while the studio, the network and the creator wrangled over this and that — product placement within the show, adding another ad break, creator’s salary, blah, blah, blah.

The 3.5 million who tuned in at 9 p.m. ET to welcome back the boys of Sterling Cooper Draper Pryce is 5.5 million FEWER than the crowd that collected at AMC on March 18 for the season finale of AMC’s monster hit — zombie drama “The Walking Dead.”

(After the 9 p.m. season opener, AMC immediately replayed it at 11; the two telecasts cumed 4.4 million viewers, AMC said.)

While the public regarded “Mad Men” as but one of many entertainment choices Sunday night – “Desperate Housewives,” for instance, attracted 8.7 million viewers, and “The Good Wife” 9.3 million at 9 p.m. on Sunday -- the media’s hyperventilation over “Mad Men’s” return goes down as one of the most convincing demonstrations of mass hysteria since Mercry Theatre’s “The War of the Worlds” in ‘38.

Why, in the days leading up to, and in the immediate aftermath of, the series’s return, The Washington Post alone contributed:

*A photo gallery about “Mad Men” fashion for sale at Banana Republic

*A Who Is Your “Mad Men” Style Icon quiz

*A report on: What If ‘Mad Men” Took Place in 2012?

*A photo gallery on: Who are today’s “Mad Men”

*A photo gallery on: Catching Up with “Mad Men”

*A photo gallery on: Ads From the “Mad Men” Era

*A going out guide about celebrating the return of “Mad Men”

*A going out guide on the best bars for a “Mad Men” vibe

*A blog entry on ads from the “Mad Men” era

*A “Mad Men” Look real-estate contest

*A blog post about “Mad Men” baby names

*A discussion of race issues in the “Mad Men” season debut

*A Choose Your Own Adventure “Mad Men” game

*A piece on how to host a “Mad Men” worthy cocktail hour

*A piece about a song in the “Mad Men” premiere

*A Make Your Predictions for the “Mad Men” season debut

*A preparatory guide to “Mad Men” season debut

*A live blog/chat during the “Mad Men” season debut

*A review of the “Mad Men” season debut

*A recap of the “Mad Men” season debut

*A live chat following the “Mad Men” season debut

And, of course, this ratings column — and, who knows how many stories yet to come.

But, the Post did not stand alone in this orgy of excess. One Reporter Who Covers Television — who apparently has a sense of shame — the LA Time’s Joe Flint tweeted Monday when the numbers came in: “ ‘Mad Men’ draws 3.5 million viewers. I didn’t know NYT’s staff was that big.”

View Photo Gallery: Since season 4 of “Mad Men” ended in 2010, here’s a reminder about the state of the employees of Sterling Cooper Draper Pryce and residents of the Francis family. “Mad Men” returns to AMC on Sunday.