In the late '90s there was a place that did something like that. That was a time of slow internet connections, with a majority still on dial-up.
They had a product for Windows computers that provided a caching, prefetching web proxy. The deal with it was that if you let it show you adds occasionally (I think it was whenever you launched your browser to your homepage or once a day if you visits to your homepage were less frequent) you could download all of the company's other Windows programs and use them free as long as your browser was configured to go through the proxy. These were programs that normally were sold on floppy or CD-ROM for $20-40 each.
The way the ad delivery worked is that the proxy would download ads, which consisted of an HTML page and some additional data. When you went to your homepage the proxy would serve up one of the ads instead, with a link inserted to take you to your real homepage.
There was a Forth-like language built into the proxy. The additional data for an add could include code written in this language, which would be run when the proxy was choosing an ad to show. The code had access to various things the proxy knew about the local system and user. It did not have any access to the internet. The code would decide how strongly the ad would like to be shown at this time.
The only thing that went back to the internet in regard to ads, as far as I remember, was counts of how many times each ad was shown. (Not that it would have mattered much if more went back. As far as I know the proxy didn't really know much about you other than the physical characteristics of your computer and your internet connection. I don't think they had gotten to the point of trying to infer interests from browsing habits).
This particular approach would probably not be feasible today. They only had a handful of ads available at any one time, with the inventory changing slowly by today's standards. It did not take much resources, even for modem users, to download the entire ad inventory and keep it up to date.
Can you imagine trying to put Google's entire ad inventory on every PC, and keep it up to date, so that the client can choose the ad entirely locally?
The entire Google ad supply does not need to be downloaded, just a relatively brief catalog (which compresses well) of live edge URLs and metadata (keywords, essentially), updated as new deals for a given region with large enough user base come online, and old deals expire.
This type of thing is also generally considered malware today. As a person who used to do IT support for a university, one of the most common malware issues would be Chrome extensions or whatnot switching your homepage to point to a ads-infested search engine instead of Google, and redirecting all search engine websites to the ad-infested one.
They had a product for Windows computers that provided a caching, prefetching web proxy. The deal with it was that if you let it show you adds occasionally (I think it was whenever you launched your browser to your homepage or once a day if you visits to your homepage were less frequent) you could download all of the company's other Windows programs and use them free as long as your browser was configured to go through the proxy. These were programs that normally were sold on floppy or CD-ROM for $20-40 each.
The way the ad delivery worked is that the proxy would download ads, which consisted of an HTML page and some additional data. When you went to your homepage the proxy would serve up one of the ads instead, with a link inserted to take you to your real homepage.
There was a Forth-like language built into the proxy. The additional data for an add could include code written in this language, which would be run when the proxy was choosing an ad to show. The code had access to various things the proxy knew about the local system and user. It did not have any access to the internet. The code would decide how strongly the ad would like to be shown at this time.
The only thing that went back to the internet in regard to ads, as far as I remember, was counts of how many times each ad was shown. (Not that it would have mattered much if more went back. As far as I know the proxy didn't really know much about you other than the physical characteristics of your computer and your internet connection. I don't think they had gotten to the point of trying to infer interests from browsing habits).
This particular approach would probably not be feasible today. They only had a handful of ads available at any one time, with the inventory changing slowly by today's standards. It did not take much resources, even for modem users, to download the entire ad inventory and keep it up to date.
Can you imagine trying to put Google's entire ad inventory on every PC, and keep it up to date, so that the client can choose the ad entirely locally?