Quote from: JorgeStolfi on February 01, 2015, 02:13:38 AM

Quote from: mestar on February 01, 2015, 12:53:39 AM

Assume all daily bitcoin volume are usefull transactions, this will give us an upper bound [to bitcoin's value as currency].

A good fraction of the transaction volume in the blockchain is definitely not payment for goods and services. Much of it is coins moving between addresses that belong to the same person, such as hotwallet/coldwallet flow. Add to that tumbling, deposit and withdrawal to exchanges, etc. Here is a summary of partial analyses that identify various non-commercial components of the traffic.

Bitpay processes about 1000-2000 BTC/day, but almost all of that seems to be miners paying bills and/or equipment. Let's say that the real use for e-comemrce through BitPay it is 500 BTC/day. Multiply by 20 (wild guess) to estimate the world total by all processors and by direct bitcoin payments. We get 10 kBTC/day of e-commerce. That is still only 5% of the ~200 kBTC/day blockchain transaction volume (even after excluding apparent change-backs from the latter).

At current prices, that would be about 2 million USD/day. If there were no speculation, each of the 13 million BTC in existence would be unavailable only between being bought by a customer and being sold by the merchant to another customer. If that time is at most 30 days, then the 13 million coins would be storing at most 60 million USD. That gives about 5 USD/BTC. If half the coins were locked up by long-term speculators, the price would still be ~10 USD/BTC.

So your entire valuation is based on "Multiply by 20 (wild guess)", yep highly accurate.
Please provide source links for the numbers you come up with next time.