Personally I dont think its an issue, but for those who are overly concerned about privacy issues regarding ads in gmail, while reading this article Yahoo Boosts Email Space in response to Gmail on ./ , I came across this 'interesting' comment on how to get rid of ads in gmail:
how to get rid of ads (Score:5, Interesting) by supernova87a (532540) on Tuesday June 15, @09:46AM (#9429026) For those who might be curious, I found an easy way to get rid of ads when reading your gmail (if for some reason, ads really bother you).
Just ask everyone to put the word "died" at the end of their messages. Gmail has this filter that tries not to be too insensitive by plastering your browser with ads for caskets next to news that Uncle Bob just died, so I guess it searches for words like that.
I tried with the words "disaster", "died", etc. and they all caused ads to disappear.
It might be creepy though after a while if every email had the word "died" at the bottom.... )
Spooky? Morbid? But effective, you bet! So, is "Died" gonna be the new sig line? :)