The mistake is this. My partner Sudeshna is an official advertiser on Bing, and I manage the account (rather, used to manage, as of late we are not doing active PPC on Bing given our updated business focus). Now, for those who don't know, Bing and Yahoo use the same ad platform - that is, ads given to Bing also carry over to Yahoo.
So, Bing just now sent us an email newsletter. And incidentally, the mailbox to which it sends (Sudeshna's regular professional mailbox) is forwarded to a specific Yahoo account.
Guess what Yahoo said about the email coming from Bing (that is, their very own ad network for all practical purposes)?
They classified it as a JUNK and sent if off to the SPAM folder ... (And not, before anyone starts thinking differently, it was not a phishing or spoofing or anything, it was a genuine email from Bing.)
Oh goodness, the Irony! How the big corporates can mess up!!!
I thought it may be worth a share, as it is light and funny, and can make your day. For those who think they make mistakes and blame themselves, cheer up, even the biggest guys can make mistakes of the most unimaginable types.