Earlier quoted context omitted.
That's how I felt about Dogecoin at first, but their silliness seems to have generated an unusually nice community. I'm starting to think that's a more important factor than I'd realized. It's taken them to #7 in market cap, despite being technically a straight copy of Litecoin. http://coinmarketcap.com/
The community, and particularly the generosity of tipping, seems to have been a driving factor. There are already multiple "tipping bots" on Twitter, which will give out Doge on command. There's speculation that a similar functionality for Facebook would be like strapping SRB's to the side of the Doge moonrocket, and give it Much Velocity.
You mention the generosity (which I agree with), but also the act of online tipping is a use case that crypto-currencies handle substantially better than me putting a dollar bill in a paper envelope and mailing it or paying a 25 cent transaction fee to tip 10 cents.