Which Comes First, the Product or the Promotion?

I often answer marketing strategy questions on social networking sites, which typically lands me new clients. While I was on LinkedIn's group called eOffice, I read the following posted question:

Which comes first, the product or the marketing?

I stumbled upon this post by the genius Seth Godin, The Marketing Guru. “Well, if you define marketing as advertising, then it's clear you need the product first (Captain Crunch being the only exception I can think of... they made the ads first.)
This great clip from Mad Men brings the point home. If the Kodak guys hadn't invented the Carousel slide projector, Don Draper could never have pitched this ad. But wait. Marketing is not the same as advertising. Advertising is a tiny slice of what marketing is today, and in fact, it's pretty clear that the marketing has to come before the product, not after. As Jon points out, the Prius was developed after the marketing thinking was done.

Jones Soda, too. In fact, just about every successful product or service is the result of smart marketing thinking first, followed by a great product that makes the marketing story come true. If someone comes to you with a 'great' product that just needs some marketing, the game is probably already over.” http://sethgodin.typepad.com/seths_blog/2009/02/which-comes-first-the-product-or-the-marketing.html

Then, I replied with the following:

As you already know, Seth is among the best in the industry. So, to agree with him is a bit redundant. But, since you asked, it is definitely the promotion/marketing. If you haven't already read Tim Ferriss's 4-Hour Work Week book, you'll find in there several simple ways to test, at least online, the sales process, including all marketing channels and finally to the point on a web page that someone gives their credit card information.

If you can get traffic to your site, convert enough of them to either register for some free report or actually make a purchase (with the last page saying, "Sorry, we are in the product launch phase, your credit card has not been charged. We will notify you when the product is available."), then you'll know you've got the right marketing message and the right sales process.

One key for online traffic via Google Adwords is to apply a filter to your ad so that you only get people clicking through who are most likely to make a purchase. Often, you'll see ads that give the price ranges of the products. So, if viewers are not ready to spend at least the minimum, they will likely not click. Lowering your marketing cost is equivalent to making more sales.

If you can develop a strong ROI by testing one or more marketing / sales process strategies first, for a product that you plan on developing, you will 1) be able to adjust the actual product's features according to what is going to sell better and 2) know that once the product is made, you can quickly set up your marketing channels and get them sold immediately.

In another OFFLINE approach, you do surveys. Simply 1) determine a psychological profile of your ideal client, 2) locate them locally (once you know someone's preferences, you'll know where they shop/eat), and 3) canvas your ideal clients, meaning, ask them in person or over the phone all the market research questions. One trick is to get permission to set up a table in front of where your ideal clients shop (and if you have voter registration forms on half of your table, no one can deny you!).

Even if 20% of respondents don't reply accurately (some people have a hard time predicting their own future behavior), so long as the majority reply accurately, you'll have some primary market research that will help you set up a proof of concept / feasibility study and both convince yourself that you have the right product at the right time, and you'll then know how to send the right message to the right people.
Since you know Seth's work, I'm guessing this is all review for you. However, perhaps others on this group would find some of what I explained of value.

So, do you have any stories that showcase this principle at work?