1) I mine Litecoin/Dash in background when I use my computer.
2) With my CPU settings, I make around 2 cents/day with the actual LTC/DASH price.
3) Quite is easy to setup, so almost no time required.
4) The extra heat I generate is used to heat my basement during winter time, so almost no loss for the extra electricity.
5) I want to support the LTC/DASH network, that's my first incentive.

I hope this answer your question.