Before I'd heard of warmshowers or this site, I saw a road-worn couple outside my local library and invited them home. They were Germans, on their way from Alaska to Argentina. They stayed five days, resupplying and fixing things and having a great old time with my musical instruments and such. I was the first American to invite them home. Their trip was very successful and we remain in touch.
I've done that many times in the past, and they were the most interesting. I've hosted many times with warmshowers now that we're in the Information Age. I've been the recipient of so much similar hospitality throughout my touring career, starting in the 70s, it's unconscionable to me not to offer it.