I can't help but think the only long-term way to reduce the effectiveness of these kinds of SEO tricks is to remove all storefronts from Google results. Even that isn't foolproof certainly, and I'm sure that online shopping sites will then just use non-store entry pages. But these SEO tricks work because many people, when they want to buy something, just go to Google and click on the first link presented, which I don't think anyone knowledgeable about web search will think is a good idea. That behavior has to change, and until Google gets serious about informing users about it, or Google somehow loses its place as the #1 search provider and whoever takes its place does so, SEO will probably continue to be big business, and Google/Whoever will continue having to run around putting out little fires.
The free market's whole point is to kill failures, so no doubt there is many.
The free market does not have a point. The idea was to create a financial system out of the general economic trading that has been with man since prehistory. An exchange of goods and services. There is a rough justice to such bartering, given there are no great differences in wealth and power between the participants.
What we have now, however, is not this thing, and I'm glad of it. The primary sellers are huge corporations that pursue every legal avenue available to maximize profits, including patents, licenses and copyrights. When the laws do not favor them, they lobby to get the laws changed. To them it has nothing to do with fairness; it is entirely a cost-effectiveness equation.
Regulation, at its best, is the only really effective shield against this kind of rapaciousness. That's not to say it's always good, but to decry all government intervention is to also bash the only check on corporate power available to us.
Isn't life wonderful when we just let the government do things?
Sometimes it is. There are unquestionably things government is best suited to do. Regulation to take the sharp edges off the free market is one of those things.
As far as corn prices go, it's unlikely that ethanol is a big part of that, and Pepsi and Mountain Dew release their "throwback" line as a small thing, not nearly in large enough quantities to lend credence to your theory. And to describe the market for corn as "free" is ignorant at best, and disingenuous at worst; government farm subsidies play a substantial role in the price of corn in the U.S., which in turn has fueled high fructose corn syrup's ascendancy as universal filler-sweetener in this country.