贴春联 (tiē chūnlián, pasting Spring Festival couplets) is a key tradition during Chinese New Year. Red paper with auspicious phrases is pasted on both sides of the door for good luck.
usage
In modern Chinese, 贴 is also used for digital 'posting': 发帖 (fā tiě, to make a forum post), where 帖 (tiě) is a different but related character meaning 'post/note'.
Shell radical on the left - the indexing component. The earliest sense was a monetary one: to attach extra coins to a transaction, hence supplement or subsidize. From this physical attaching grew the broader meaning of pasting or sticking. Same money family as 财, 货, 贵, 贸.
占 supplies the sound, with the initial drifting from zh- to t- in this phonetic family. Same right side appears in 站 (zhàn), 沾 (zhān, to moisten), 粘 (zhān, to glue) - all clustered around the sticking and standing-still meanings.
