Although a website's availability, in itself, does not constitute the purposeful availment of the resources of a jurisdiction, a steady and predictable flow of commerce to the jurisdiction can constitute sufficient purposeful availment to justify a reasonable assertion of jurisdiction.
http://media.ca1.uscourts.gov/pdf.opinions/18-1195P-01A.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.