Sales tax isn't paid on trades. When you trade in a car for $2k off a $10k car, you only pay taxes on the difference: $8k.

And if you grow oranges on your property that you never sell, you never pay taxes on those oranges.

Not in California.

If you accept a trade-in on the sale of a vehicle, the allowance for the trade-in cannot be excluded from the amount on which tax is based.

For example, if you sell a car for $20,000 and accept a trade-in valued at $4,000 as partial payment, tax is based on the $20,000 selling price.

Source: http://www.boe.ca.gov/pdf/pub34.pdf

I shouldn't have used vehicles since they are a special case in some states. At the federal level, taxes on barter income match my description. [0] Taxes are still zero if the company can claim the fair market value of the services they offer you equal the value of your clicks.

[0]: https://www.irs.gov/taxtopics/tc400/tc420

Never heard of this, probably because in my state it doesn't apply. In 42 out of the 50 states (excluding California, Hawaii, Kentucky, Maryland, Michigan, Montana and Virginia [Oregon has no sales Tax]) however, this does apply.

Still though, the example is a good one. You're trading your data for a service. There isn't anything to tax.