Does porn addiction hit the same brain area as nicotine or alcohol addiction?

Yes: The brain is very complicated so that there is usually a circuit of several areas affecting a function. Addictions in general are believed to energize the 'reward circuit' involving an area called the nucleus accumbens communicating with several other areas with the neurotransmitter Dopamine being a primary activator. Wikipedia has a good summary and links under 'brain reward center'.

Cravings: The compusive desires do not emanate from the nucleus acumbens (non-compulsive wanting does). Rather, the compusive thoughts for all addictions, substance and process, come from the Dopamine and glutamate release in the dorsal striate cotex (contiguous areas of caudate and putamen) this is often precipited by some specific trigger. This release presents a target for treatment.