Why can places get a さん suffix when they are not a person?

Question

For example:

• 薬屋さんに行った。
• 初めてくるお風呂屋さんは楽しい。
• 講堂さんにてライブがあります。

First, what nuance is added by adding a さん?

Second, can this be done with any place?

Third, it seems like the frequency of usage varies a lot by word. 風呂屋さん seems to be really common when talking about the subject while 美容院さん or 講堂さん seem significantly more rare (but as in the example, not unheard of). Is there a reason for this outside of the nuance indicated in the first reason?

Fourth, while not particularly important, I'm somewhat curious how this came to be etymologically. It feels like it would be personifying a place, but it doesn't really seem to have that nuance from what I have seen.

Answer 1

The effect of さん added to a noun that represents a shop is not that different from when it's added to a person name. さん makes the noun sound friendlier and more casual. It's mainly used in informal conversations (usually in the home) to refer to nearby small shops. It's typically attached to a wago ending with 屋 (e.g., 魚屋さん, 八百屋さん, 床屋さん), so you can remember this usage is basically a part of 屋さん. お寺さん is also used by many. It's very rare after a kango such as 美容院, 映画館 or 駐車場.

However, さん has another usage; it can be added to an organization name, and this type of さん is used in not-so-formal business conversations where 御社 (or 貴校, etc.) is an overkill. For example, you can hear ソニーさん, IBMさん, みずほ銀行さん, 京都大学さん, and so on. By extension, 美容院さん, 映画館さん, ライブハウスさん and so on may be heard in business-related contexts (e.g., この新商品は全国の美容院さんでお試しいただけます).

Either way, I personally haven't heard 講堂さん; it's a kango, and it's not a place closely related to business.

As for the etymology, I think there had been no rule that you have to use さん only after a person name. さん is etymologically from 様 (さま), whose original meaning is "state/appearance". See this, too.