Isn't that where difficulty factors in? If enough people quit mining the difficulty should fall so low that eventually it would become profitable again.
Technology is going to improve also, mining should continue to get faster/cheaper.
No, not really. What I'm saying is that with everything working as it should... difficulty doing it's thing to regulate block discovery times, and the design of DGB being such that the block rewards reduce over time... there comes a time in the not too distant future where block reward drops to less than 1000 (around 5.5 years out) and then at around 10 years out it's approaching 100 DGB/block. Point is... the currency is only useful if it can be used... and it can only be used if there are miners to verify transactions...maintain the blockchain.... therefore without miners... well... you see where I'm going with this.
It's not just a DGB question... any long term coin that has the potential to survive... what happens if nobody bothers to mine anymore?
I see what you mean, I've actually wondered about that too (why mine when it approaches 0). But if the currency increases in value, it might be worth it to still mine with the decreasing block rewards (taking technology into account) even when the reward drops to 100, or 10, or maybe even 1 (or less), especially if it ever reaches the $1 per DGB value. (those are big IFs though...)
Assuming 3.5 days per block payout reduction, here's approximately when DGB would drop below certain block rewards (a little over 4 years for a factor of 10):
1000 July 2018
100 December 2022
10 May 2027
1 October 2031
0.1 March 2036
0.01 July 2040
I'm sure the problem will be addressed if/when it ever gets to that point...