Sure, there have been tulip crazes and such like, people paying vastly more for a product than it was objectively worth. But with the Pet Rock, you finally had the apex, the holy grail of marketing. Our usual snarky definition of marketing is "getting people to spend money they don't really have on something they don't really want." (And at Christmas, perhaps for someone they don't really like).
This presaged a new era of marketing, though, the sort of thing that would have made Don Draper break one in his no-press slacks. Here was something that people bought that had no objective worth whatsoever, that was purchased not just ironically but semiotically, a cultural signifier that you were in on the joke. This was something you could literally find in your backyard, thrown in a silly package, something that all observers could see had no intrinsic value, lying inert, much like the recorded catalog of Kanye West. [Ed: Hi-yoooooo!]
Since PR and marketing are the rackets that really run the industrialized world, far larger than the usual finance / health care / higher ed beasts combined (indeed, by definition, all rackets depend on PR and marketing in order to get people to accept the ripoff and ask for more), it makes sense that the scumbags who run the political circus would sit up on their hind legs and take notice.
As Mad Men finishes up its run, it has noted repeatedly that that era was where PR weasels finally crystallized their understanding that people buy the sizzle at least as much as the steak. An even more important realization was that many people are more than willing to buy just the sizzle (fo shizzle), and not even worry about the steak.
If you're old enough to recall the Pet Rock, then you probably also recall a time when Ronald Reagan was not taken seriously as a viable presidential candidate. Then in the mid-'90s, a dimwit fuck-up son of another preznit name o' Gee Dub Bush (aka Fredo Arbusto) first beat a popular governor in Texas, and then clawed and cheated his way into the White House. But the bar had been lowered.
Several years later, Sarah Palin, and now Ted Cruz. Not to mention the countless jabbering assholes and buffoons that litter the Senate and especially the House, brazen dickheads like Louie Gohmert and Scott DesJarlais, whom you wouldn't have allowed to clean your gutters twenty or thirty years ago.
In "inventing" a fun, silly way to make a few ducats for himself and his (I shit you not) investors, Gary Dahl inadvertently also demonstrated that the bar can always get lower in this country, even in more important areas of life, with the proper marketing.