Relevancy of Online advertising, a disaster?

In our industry, throwing up advert much relevant to the content and to the Targeted Audience is the prominent factors which determines a good advert.But sometimes, it might leads to disaster.One such case which, I came across today when, I happened to check my email on my 30gigs account.When I opened up the 'Inbox", I saw a leaderboard(728x90) Google Adsense advert on the Top, campaigning to create a gmail account.

Refer to the screenshot below

So whose loss, whose gain?

• Can we blame GoogleAdsense for showing this advert?
• Should we blame the 30gigs team for placing google adsense on their inbox ?

We cannot blame either of them as, GoogleAdsense does not know the 728x90 property details on 30gigs.At the same time even 30gigs does not know what are the Scheduled ads that would be displayed.So sometimes things are inevitable.

So whats the lesson in the store?

Too much of Relevancy not only gets you conversions, but also eats your cake :-)