When people are looking for friends. Someone told me it was rude that a person I just met left after 20 minutes. They say at an hour is courteous unless something horrific happens.
(It may be worth noting that I look female, this person is male, and we exchanged contact info before I mentioned my boyfriend later in the conversation.)
It's been several days and no contact.
Then they were probably just being polite and enjoying your company. It's not a bad thing, and I'm sure they enjoyed the time meeting you. But I wouldn't expect to ever hear back from them. Not every connection will be permanent, but that doesn't mean they didn't matter.