In the past few years we have seen the rise of a new breed of popular websites. And broadly I would classify them into two categories. The sleek, cool ajax based web 2.0 websites and the community driven websites.
For a website to become popular, it needs to serve a purpose in a much better way than others. And ajax is a cool way to better the existing way of delivering data.

Two types of popular websites:

1. Cool Ajax based websites:

It started with Google showing the world that asynchonous javascript and dynamic html can be used to code websites which are sleek and user friendly. These technologies have been around for quite some time but it needed someone like Google to show the world that its possible. With Google Maps and gmail, the web moved to its second generation, the Web 2.0. Yahoo soon started to ape Google and come up with their new! email look and their yahoo maps. Travel websites now allow you to update the results page dynamically (without page reload). Real estate sites like zillow.com became great hits just after its launch.

2. Community driven websites:

YouTube.com was the site that showed the world that if you can get the support of the community, your site will never complain about traffic. It takes big companies like AOL to run a content based website. But if you can involve the users and motivate them to submit content which other users like .. you have hit the jackpot. And for that you do not need huge advertising dollars and maintenance costs. You will no longer need a sleak cool website. Community websites like Digg.com and del.icio.us have simple easy to use interfaces but the content is extremely rich and these websites are an indication that “Do not evil” and “Earn Goodwill” are the strongest mottos for any not-so-big web entrepreneur. YouTube and myspace thrives on content from users and are the hottest spots on the internet. If one could spread goodwill simply by using money, Microsoft would have a hundred myspace.com and digg.com. If just technology was an issue, Google would have continued using Google Videos and would have never bought youtube.com for billions of dollars.

So made for adsense websites will be around in this world as long as adsense is around but these sites will never make it big. To make it big, you need to make a genuine attempt to solve a problem in a better way and for a change not think about how much it is going to earn you in the next 12 months !!