Because you can sell targeted ad space for a lot more money.
Also they allow people to opt out of tracking, which is probably how they kept the govt off their backs thus far. But of course few people are aware and savvy enough to opt out of systems which allow it, which is why many want to change organ donation to an opt-out system rather than opt-in for example.
Also they allow people to opt out of tracking, which is probably how they kept the govt off their backs thus far. But of course few people are aware and savvy enough to opt out of systems which allow it, which is why many want to change organ donation to an opt-out system rather than opt-in for example.