Each of these follows the same pattern of “[People type] are doing [action]. This is great because [benefit]. This is painful because [cost].”.

I tried to think about some financial products this way.

PayPal: people are sending money to each other. This is great because it's handy to be able to pay a person who doesn't accept credit cards and isn't near you. This is painful because you can only send money to other PayPal users.

Money Market Funds: people want to earn interest on their savings. This is great because they can get more yield than the ridiculous interest rates offered by deposit banks on savings accounts. This is painful because you can your rate may be variable and you may not be covered by FDIC.

I think Bitcoin could solve people's problems in both these cases, but it doesn't seem like the trade-offs are acceptable...or something, because I don't see bitcoin eating much of their market share.