Google has nothing to fear even to have its nearest rival in web mail to advertise their email service right on its Gmail as shown on the below. Gmail still fresh from being the no. 1 web-mail in India, which is previously Yahoo Mail strong hold for very long time.

Being dominant in online advertising, Google is open for anyone to advertise their own service

On the other side, Yahoo is taking the bold move to have this advertisement, considering that, Gmail users are most likely use Yahoo Mail or Hotmail, including myself before. Yahoo Mail has received numerous enhancement over the year, including introducing AJAX based interface, open application and become even more social-like website, with hope to gain back the market share it is losing so far.