Is it coincident that all planets with tight orbit are tidally locked to their parent body? I know mercury is tidal locked to our Sun like our Moon is to Earth, is it merely coincident or there is some sciences behind it? Some man-made communication satellites are also tidal locked to Earth! I think it is intentional so that there is minimum interruption for signal transmission, they used thrusters and gyro to help them to always point toward Earth.
This is a physical result: 


  The change in rotation rate necessary to tidally lock a body B to a larger body A is caused by the torque applied by A's gravity on bulges it has induced on B by tidal forces.


Stellar bodies get tidally locked with time. You even get graphs like there.

On how long it generally takes, from Wikipedia

$$t_{\text{lock}} \approx \frac{\omega a^6 I Q}{3 G m_p^2 k_2 R^5} $$

Where $Q$ and $k_2$ depend on the constituents and age of the satellite, which themselves evolve with time. Difficult to estimate. Moreover, you rarely know the age of your system.

But it explains that for long-time established system of relatively close bodies, tidal lock is generally the case. The more tide there is, the quicker it gets.