In Pokémon games you get it from beating trainers. On LV you get them from logging in daily. Hope this answers the question.
You earn Poképoints by posting here on LV, as well as receiving a random amount each day you log on to the site. We also give out points as rewards for contests and members can donate their point to others if they want.
I thought it was still common knowledge, but I guess the daily logins have kind of replaced it as the primary source of Poképoints for most people. Posting anywhere outside of the Game Corner will net to Poképoints, though I don't remember how many points per post you get.
