It seems that Microsoft has suddenly discovered that Google puts contextual ads in emails. Cleverly, Microsoft is terming this as 'Google reads your email', and is making enough noise about this fact.
The question is Google's contextual advertising is not a new thing. This is how Google makes money. Then why Microsoft has woken up just now? Answer obviously is recent launch of Outlook.com by Microsoft.
This is the problem with Microsoft. All this is not about any principle. This is just a marketing campaign to sell its competitive product.
So this is just business.