My experience was very disappointing
My experience was very disappointing. I bought an Amsterdam Travel Ticket online from GVB (via Tiqets), expecting I could use it right away. But instead, you only get a barcode that must be scanned at a machine to get the actual ticket.
The problem: At Amsterdam Centraal, the machines were either broken or did not scan the barcode. So I had to find the GVB office outside the station to get my ticket.
This makes me wonder: what is the point of buying a ticket online if it is more difficult than buying it in person? It is not user-friendly at all and definitely not tourist-friendly.