>Hi everybody,
>
>This message seems incorrect to me (in a tooltip):
>
>'Statistical information about this item's activity'
>
>I think it should say
>
>'Statistical information about this item activity' (no preposition here).
>
>What do you think?
>
>Thanks in advance.


The first is correct
>'Statistical information about this item's activity'

It is short for: Statistical information about the activity of this item

The 's in item's is known as the saxon genitive http://encyclopedia.thefreedictionary.com/Saxon+genitive


There's the same in Russian
see: The genitive case in Slavic languages:

http://encyclopedia.thefreedictionary.com/Genitive+case

Possessives
To indicate possession, the ending of the noun indicating the possessor changes to а, я, ы or и, depending on the word's ending in the nominative case. For example:

Nominative: "Вот Антон" ("Here is Anton"). 
Genitive: "Вот карандаш Антона" ("Here is Anton's pencil").