Strong e-id is often needed when logging in also to non-banking services. Reusing bank e-id also there - especially in the public sector - is something of the most sensemaking aspects of also otherwise much needed public-private co-operation.
2011 was a great year for bank e-id (TUPAS) - the alternative (a state issued smartcard) is not used at all. It is to be hoped that no further countries will try the citizens smartcard route (our dead on arrival experience should deter). Background here: https://www.finextra.com/blogs/fullblog.aspx?blogid=2820
Bank e-id tools can also be had by the non-banked. Close to 30m transactions in Finland would translate to 2,1 bn in Europe. Massive cost-saving - and would deliver much faster public sector e-services.
Using bank ID for login to third parties started in 1993 in Finland. Now at least Sweden, Estonia, Norway, Denmark are using it - and at least Canada is joining soon. It would be interesting to see if somebody can come up with real counterarguments in the
still-out-countries.
e-Commerce payments (like the Dutch Ideal) was introduced in Finland in 1996. Good growth also there. Again it is a question of economy of repetition (same procedure as when paying bills), economy of reuse, economy of scale, economy of scope and economy
of trust.