I can't get into too many details, but in the past 5 years, I did some consulting for a small company that did nothing but affiliate sales.

I don't know what their total revenue was, but I know that they were paying for 3 full-time consultants billing on the high-end, 1 graphic designer, a full-time accountant, a business manager, 3 SEO people (full time as well) and the owner.

So, there is definitely some money to be made there, I just don't know the actual ratios of blood, sweat and tears vs. sheer luck.

>>> building traffic to some website for adsense and affiliate sales for the same?

There are basically two main paths you might take here. I have a friend who made a fortune by spamming search engines, but his peak was about 6 years ago, when it was quite easy to game google for profit. Now he has about 1.000 (one thousand) interlinked domains with affiliate links. Of course, as Google algo improved, his sites are slowly de-ranked, but there is also MSN search and Yahoo, and his "imperium" is so big, that he already earned enough to live confortably for the rest of his life.

But anyway, he says that starting now this would be much harder, because Google already closed many gaps. It is doable, but much harder.

Another way is to use "white hat" way, i.e. building normal content like cool gadget blog. But this is also harder that it looks, especially to build "great team of 4 paid writers". Author don't elaborate more about that, but this I think is non-trivial. There need to be some unique vision plus writers who can execute it by writing engaging content.

What would really bother me with that business model is that you are highly dependent on your Google rank. You can lose all your revenues instantly if you are removed from the index or outranked by a competitor.

I disagree with this. A site like this isn't getting the bulk of their search traffic to their homepage. They have thousands of minor pages indexed for search terms that only a handful of people search for. Multiply this by 10,000 and you get their search traffic (long tail, blah blah blah) There's no "one page" that if there's a large rank drop will affect.

Note, this is very different than, for example, an e-commerce site that sells "widgets", and is ranking very well for the word "widgets". For them, a ranking drop could be devastating.

Now, that being said, they are dependent on Google for the bulk of their income... but there are worse things than tying your fortunes to Google's financial well being.

remember, this was for december 2007 which is probably the best revenue month for a gadget blog. i wouldnt be surprised if the average month was around half that.

That's still a lot of operating capital for whatever other ventures you wish to pursue. Figure $300K for the year... not bad, not bad at all.