newtonian gravity - Why does the moon drift away from earth?

I once saw on TV that the moon is slowly drifting away from the earth, something like an inch a year. In relation to that the day on earth what also increase in time. I wonder why is that?

Answer

This says it concisely, when describing the effect of tides:

Gravitational coupling between the Moon and the tidal bulge nearest the Moon acts as a torque on the Earth's rotation, draining angular momentum and rotational kinetic energy from the Earth's spin. In turn, angular momentum is added to the Moon's orbit, accelerating it, which lifts the Moon into a higher orbit with a longer period. As a result, the distance between the Earth and Moon is increasing, and the Earth's spin slowing down.

In fewer words: it is the tides.

Edit: I am copying from a comment:

To show the right sign, one must show that the orbital angular momentum of the Moon actually increases with the radius - despite the decreasing velocity as the function of the radius For a $1/r$ potential, $mv^2\propto m/r$ says $v\propto 1/\sqrt{r}$, so the angular momentum $L=rp=mrv=mr/\sqrt{r}\propto \sqrt{r}$ which increases with $r$. – Luboš Motl

In addition I found this better link by googling.