It depends on how you use the opportunity, really. From a
strict marketing point of view, it doesn’t make sense because technically
speaking, you are working hard to drive the traffic to your website ONLY to
drive your visitors away from your website. Why would you want to do that when
you make a lot more money when they spend more time on your website?

But if you look at it from a strict publisher point of view
with the sole intention of making money online through websites dedicated for
Google Ad Sense, it does make for a continuous stream of residual income. There
are people earning anywhere from a few hundred to thousands of dollars through
Ad sense.

Ideally, Google Ad Sense seems to be perfect for RSS feeds,
niche websites built for the sole intention of informing readers using focused
content on tight niches, forums, community sites, Q & A sites, etc.