If you neglect the dystopian aspect (which I don't have issue doing) the possibility is amazing as someone who is not immune to health problems and appreciates modern medicine.

Preventative targeted therapies lead to over testing. Even worse there is the perverse incentive of having a for profit company marketing the intersection of their products with person's potential future ailments.

Having the same information available to your doctor (or an AI, ha!) that could parse it objectively would make more sense than a single pharma company. Does anyone really think that GSK is going to suggest you take Viagra (Pfizer) over Cialis (GSK product)?

Let's not forget the massive extortion going on with drug prices as well. Also, there seems to be an issue these days with having enough independent replication of results by people who are not on company payrolls, or with selective publication of only positive results. Handing that data to one company is likely not going to result in reliable science by itself.

Or worse: "based on the $200 introductory test we found that you MAY have a higher predisposition to contracting TerribleItis-B, we urge you to get the ultimate version for $600 to be sure"

I don't see how this is any different to:

“Based on your weight you’re 27% more likely to develop heart disease or cancer, talk to your doctor about how diet and exercise can help”

Which I personally think is a very good thing, but a lot of other people see as "fat shaming" and a gross violation of their human rights.

Why is that a bad thing? Wouldn't want it popping up while I'm looking for dinner recipes, but it's a hell of a lot more useful than shoe ads. It needs to be deeply regulated -- but most ads indicating health benefits already are.

Because over-testing, over-diagnosis, and over-treatment are all associated with harm.

People bang on about early intervention, and it's useful for some stuff, but for a lot of stuff there's no evidence of a reduction in all cause mortality.

Given current diagnostic technologies, correct. I think genetic data and other types of bio data can be used to invent significantly better diagnostic tools that would reduce or eliminate the problems you talk about.

For example, we currently do not have a diagnostic test that can tell the difference between a virus or bacteria so physicians prescribe antibiotics just in case. If we did then we could reduce the use of antibiotics. Genomic sequencing won't help this case specifically, but sequencing at the proteomic or metabolic level may.

Not to mention that the majority of modern pharmaceuticals are focused on treating symptoms instead of causes. Insert argument about sick people being more profitable, etc.

Off the top of my head:

1. A lot of people come to a doctor with a specific prescription medication in mind based on ads alone and many doctors happily oblige and possibly even receive kickbacks from pharma.

How often is medication prescribed for a problem that could have been left alone? I suspect A LOT, based on how over-prescribed addictive and dangerous opiate painkillers are in USA.

We'll now be corralling those people not just on conditions they have, but also ones there is some research suggesting they are a higher risk to get. Maybe they'll even start taking something preemptively, because they have a 200% higher than average chance of developing a condition that affects 1 in 1M...

2. Once your genetic traits data gets to the adtech it's a matter of time before you'll see online gambling ads targeted based on research like this https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3638385/ and similar things

3. Negative targeting could also become a thing:

- how about you don't show health insurance ads based on genetic markers that can result in high coverage costs? or limiting your recruitment ads to potential employees that aren't likely to have or develop diabetes?

- just checking for lactose tolerance gene would exclude most of worlds non-white population - would that be OK? that same check could be used for medication ad targeting - wouldn't even have to extended dataset

I'm fairly sure I could get you a hundred examples how it could go terribly wrong if I had a couple hours.

You shouldnt be downvoted for asking an honest question. I'd answer this by rephrasing it as "What's so bad about online advertising? All they're doing is showing me targeted products that are likely to interest me." Well now think of spyware, intrusive ads with sound, popups, etc.

The general answer is that medicine is supposed to help you. But advertisers aren't paid to help you. Theyre paid to get you to buy things. And all the trickery and marketing tactics aren't conducive to getting you the correct treatment.