When reading texts in L2, (sometimes) it can be easy to infer the meaning of a word based on its usage in the text. This can work similarly when listening or conversing. (Of course, to ensure there is no misunderstanding, looking the word up in a dictionary as well is good practice.)
My question is: How does the vocabulary learned through reading/listening/conversation (immersion, more or less) stack up against vocabulary learned through study (flashcards, vocab lists, etc.) in terms of retention and proficiency?