(quote) The method used for determining the reward is to do a right shift on 50,000,000 satoshis every 210K blocks. That truncates any fractional satoshis. There are some truncation along the way. For example starting in block 6,090,000 the reward is 9 satoshis. In block 6,300,000 it becomes 4 satoshis so the block reward declines by more than 50%. Block 6,930,000 will drop the reward to 0 satoshis however only 2,099,999,997,690,000 so it looks like we will be eternally 2,310,000 satoshis (0.0231 BTC) short of the magical 21M. If Satoshi had wanted it to be an even number the starting block reward should have been a multiple of 2. For example is the first block reward had been 2^32 satoshis (~42.94 BTC) then we would have had 32 perfect halvings of the reward. 2^32 down to 2^0. A bit of trivia, the "21M" appears nowhere in the code. The entire subsidy calculation is just a handful of lines. (endquote)
Following this principle, eventually you will want to use them, particularly when others Fiat currencies go away - this is but a transition period for the next 30-50 years. The fact that there is an economy (mostly underground) that makes use of the currency as what it is meant to be (anonymous / uncontrollable / as a way to establish a trading baseline) just makes it stronger as tool for the people. As to this being another bitcoin bubble, definitely. But look at the 4 yr graph and you can see that bitcoins are seeing constant positive growth if you ignore the speculative bubbles. (Disc: I own & am long Bitcoin)