Difference in usage between “не помешает” and “не повредит”

Question

компания мне не помешает

компания мне не повредит

I wonder how they differ in usage when used figuratively.

Answer 1

They differ in the degree of usefulness/harmfulness implied. "Не помешает" implies that something can be in fact good, while "не повредит" often means that something is merely not going to do any harm.

• "Одна рюмочка мне не повредит" - "One shot of liquor won't harm me"
• "Одна рюмочка мне не помешает" - "One shot of liquor would be welcome"

And in many other contexts, when the subject is essentially harmless (like tea) "не повредит"/"не помешает" are full synonyms.

Answer 2

They both can be used figuratively in pretty much the same way:

Компания мне не помешает / не повредит.

Чашечка чая не помешает / не повредит.

Немного развлечься не помешает / не повредит.

The first thing I associate "не повредит" with is definitely harm that can be done to someone or something. And "не помешает" is like "I could do with something". So, again, if you are interested in the figurative usage (you are), you can use both expressions without a second thought.