상 = award 상품 = prize with monetary value. 경품 = giveaway; premium; something you can win by drawing a lot.

경품 must include a way of promotion

상 is something due to your good behavior or effort. it can be product, trophy, cetificate of award or all of them. but 상품 means only product (상장= 상+품 and 품 means product) and 상장 means only cetificate of award. (상장=상+장 and 장 means document or paper) on the other hand, 경품 isn't for your effort. generally, it is just given for event by lottery ~뜨리다 is attached when you want to emphasize a verb. but not for all of verbs. 깨다. is just breaking 깨트리다. is crushing or smashing. and a few verbs can use "뜨리다." 깨뜨리다, 터뜨리다, 무너뜨리다, 망가뜨리다, 떨어뜨리다. i think that is all. in addition ~트리다 is same with ~뜨리다 깨트리다, 터트리다, 무너트리다, 망가트리다, 떨어트리다. all of those are also correct.