Core marketing-industry term. 投放 literally 'to throw/release' — think of it as 'pushing ads into channels'. Pairs with specific platforms: 信息流广告投放 (feed ads), 搜索广告投放 (search ads).
register
Professional/business register. Often abbreviated to 投放 in marketing chat. A 投放经理 is an ad-buying / media-planning manager.