constant stream of visitors; thronged with callers
Yojijukugo describing a house or person so popular that visitors come in an endless stream, as if forming a marketplace at the gate. Often used in literary or formal contexts.
His house was bustling like a marketplace with a constant stream of visitors.
千客万来 also means a flood of customers or visitors, but is more commonly used in business contexts (e.g., shops), while 門前成市 emphasizes the image of a crowd at someone's gate.
From Chinese origin, literally 'in front of the gate forms a market', a classical phrase describing a constant stream of visitors.