EDIT: Not saying the argument is incorrect, just that it will not convince the public.
I wasn't making an argument, I was redressing the logical fallacy of the parent comment.
>the public will say that they will trust their own judgement
The public trusted it's own judgement before, during, and after the civil rights movement and that didn't really work-out too well in the public's favour, did it?
>...and that they are simply not susceptible to lies by politicians...
(Since this is an American board.) Do they believe that they weren't susceptible to the lies about the Iran-Contra Affair, Watergate, McCarthyism, surveillence by the government, MK Ultra, etc., either?
>...especially if they don't match with what is said in mainstream media.
See: the Leave Bus in the Brexit Referendum.
Clearly, billions of pounds are not going to the NHS, now, correct? Just because you see it and it's spread across social media, it doesn't mean it is implicitly true. All of your points were met for this example; yet, it was resultantly found to be a total fabrication. How would they account for that? Instead, will your argument now amended to be "some of it doesn't match it with social media"...?
I don't think the mechanism matters fundamentally here. I do think it is wise to consider all political speech fraudulent by default, whether it happens on public spaces or on the internet. They're all selling anyway, and if someone approaches you to sell something you know they have more to gain than you do.
Then, we have this internet which is somewhat good at targetting content based on your online activities. This internet is used by virtually everyone to do targetted advertising and promoting of products, ideas, and younameit. I find it weird this would not be OK when it comes to politicians and political parties. They're out selling as much as the next guy, and the way to do targetted advertising is online.
It is another discussion whether online tracking is good or bad, how much of that happens with or without a consent, implicitly or explicitly, but because online tracking is prevalent it would be foolish to assume that nothing you do online will be tracked. Any advertisement, political or otherwise, must be assumed to be targetted at you before interpreting its meaning.
I don't find a single thing that would make a targetted political advertisement inherently worse than any other targetted non-political advertisement or any non-targetted political advertisement.
That's becuase, in terms of consent, you're consenting to such actions by going out to the public square. You're not knowingly consenting to your life's history being sold and traded on a black market that's then used to target you for such speeches when browsing on the internet.
For your analogy to be comparative to what's going on, you should, instead, think of it in terms of a politician showing up to solely your house because you're the sole democrat in a republican city in, say, Texas. (This demonstration based on the fact that this is an American board.) This could be easily inferred from your social media, browsing history, metadata collected by the government, etc.