I had a lot of problems with this book, including some sloppy writing.
I think the Feed is supposed to be like having the Internet in your head but in the book we really only see it used for something akin to instant messaging, selling things, and there's a reference to playing games. But because the emphasis is so strongly on the Feed as an advertising venue it's hard to see why anyone would agree to it. A while back advertisers were all excited about push technology because it would open up a new avenue for advertising. Of course, it never really took off because consumers weren't getting anything for letting advertisers push ads to their desktop.
So what's in it for consumers with the Feed? I can see giving companies an e-mail, especially if it's an e-mail just for stores, because if you don't want to read the ad for the week you can easily delete it. There doesn't seem to be a way to do that with the Feed. As far as I can tell it's like everyone is tapped into a 24/7 advertising channel interrupted by a few minutes of "infotainment news." Why would anyone subject themselves to that? It's not even like the advertisers are paying for the Feed hardware to be installed.
I'd also challenge Anderson's take on American companies. I don't think "American" companies are the problem, I think it's the multinationals who have no loyalty to any country or government. While it's true that Americans consume vastly more than their fair share of resources, this book takes place more than 100 years in the future if memory serves. China and India are already on the way to following the US' bad example. I felt like that whole subplot never really went anywhere and was just thrown in to score political points.
Though speaking of points, the book does earn bonus points for pointing out the the United States is not a democracy. It's a republic. Unfortunately the explanation wasn't particularly good and I found myself confused even though I previously knew and understood the point Anderson was trying to make. (We live in a representative democracy. We elect people to decide things for us. In a direct democracy every citizen would vote on every issue).
Anderson apparently wants to leave the reader with the impression that if Violet had a stable purchase history, i.e, if she hadn't deliberately tried to screw it up, then the company that makes and installs the Feed hardware may have tried to fix it or some other corporation may have agreed to fund the research and repair.
Here's the problem. Violet essentially has an orphan disease (a disease that affects a very small percentage of the population). It's hard to get companies to fund the research for curing or treating these diseases because the base of possible consumers is so small that it will never be profitable. Violet herself is poor so a true purchase history would show that any company that helped fund her recovery would probably never come remotely close to breaking even over the course of her lifetime. Understand, I'm not saying that the companies are morally right to refuse to help her out. But I am saying that if the premise is that all corporations are greedy and care only about profit, there is no way that helping Violet makes financial sense given the facts. So while the suggestion seems to be that if she hadn't rebelled they may have helped her out, the reality is that given her financial situation it's highly unlikely she would receive the help she was looking for.
Plus, we're talking about a time frame of mere months to not only research but develop a fix for her situation. I assume it would be treated like any other medical procedure and getting government approval would take far longer than she had to live.
Even Violette and her father seem entirely reliant on the corporations. They write one nasty letter and then when they're told no they just give up. They don't try looking for alternate sources of funding, they don't consider going to the media, they just give up. Instead of writing a letter threatening never to buy anything again they should have suggested that it would earn the company(ies) good PR for helping. I know it's hard to be nice when you feel you've been wronged, but you're much more likely to get help if you're civil rather than accusatory. Though, let's be honest, there would probably be a lengthy court battle while the company hoped Violet died before they'd have to pay for the treatment/fix/research. But that would be a novel about tort reform, not consumerism).