Sometimes I get inquiries from other people through my regular email address while other times I only know about them due to seeing the little red flag at the top of the Ancestry page. In my opinion, there are probably many people who fail to look for the little red flag or do not see it due to it being so small. Perhaps Ancestry should consider enlarging the flag icon or perhaps providing some sort of larger banner saying "You've Got a Message" or words to that effect.
What is really strange is when I get a response from someone who I attempted to contact six months or more who finally gets around to responding. Better late than never, I guess.