I understand that a cryptocurrency has no intrinisc value, and that therefore its value is determined strictly by market forces, i.e. supply and demand.
I "get" (more or less) that this is how it works for cryptocurrencies that are already "up and running", but what I don't get is how a cryptocurrency's market gets started. I mean, there are over 800 cryptocurrencies already, with a couple dozen pretty well-known, right? So apparently starting one isn't very difficult. But when someone starts a cryptocurrency, how does his first (and his second, third, etc.) "coin" acquire any value in terms of traditional money? I mean, I understand that the first transaction gets the cryptocurrency's "market" going, but that transaction is internal to the currency, right? It does not establish a value relative to a traditional currency.
I also don't get who would enter into that first transaction anyway. If some person tells me "Hey I started a new cryptocurrency, so far I've mined 1 unit of it. Can I use it to buy a can of beer from you?", why would I ever say yes, given that there is no way to determine what is a reasonable "starting value" for his currency?
(I did read up on a bit ICO's, but I don't quite get that either. OK, some "company" proposes to create a bitcurrency, and investors can buy into it prior to its creation. Does that mean they buy a certain number of the yet-to-be-created currency? In that case, again I don't understand what possible basis there could be for assinging a specific value.)