Yes, you can get addicted to pot, you can be addicted to any drug. You can end up not only wanting but craving a high that requires you to have this drug. It becomes a habit that is very hard to break and that is why people continue to smoke it.
I believe people can get addicted to pot because it contains THC, THC is responsible for the "feel good" high people get. I believe the "feel good" high is what people get addicted to, pot has THC therefore making it one of the many things people get addicted to just like other illegal drugs than contain "feel good products".
People who smoke pot can seem to be addicted because they sometimes smoke it often. However, they also seem to be able to go without it for unpredictable amounts of time without going through any physical withdrawal symptoms. It seems they just enjoy it, and if they are addicted to anything it is not the drug itself, but the enjoyment.
Addiction is a medical term that means a person is physically dependent on a certain substance, and without that substance, the body suffers. Marijuana is not an addictive drug. People may abuse the drug, since it does cause feelings of well-being, and this can be detrimental to their relationships, career, life, etc, but no, the body does not get addicted.