California now has in place the below embedded affiliate nexus tax law. From the preface of the bill:

This bill would include in the definition of a retailer engaged in business in this state any retailer entering into agreements under which a person or persons in this state, for a commission or other consideration, directly or indirectly refer potential purchasers, whether by an Internet-based link or an Internet Web site, or otherwise, to the retailer, provided the total cumulative sales price from all sales by the retailer to purchasers in this state that are referred pursuant to these agreements is in excess of $10,000 within the preceding 12 months, and provided further that the retailer has cumulative sales of tangible personal property to purchasers in this state of over $500,000, within the preceding 12 months, except as specified.

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