Affiliate based sites. What are the pitfalls?

I am thinking of creating a site which has content based on affiliate products where revenue comes from affiliate commissions. The site will be of high quality, human created and edited. I am planning to use a vertical market and which is nit highly competitive. I know that AdWords campaigns based on popular keywords are very competitve and expensive. This will be a side/hobby business so by no means I am planning to give it too much time to make lots of money. If it makes $500/month, I will be very happy.

Anyone did something similar and has some advice? Any markets or products you recommend without going into crowded or very competitive areas? I don't want to spend too much time or money on marketing.

I get the feeling you are underestimating the amount of work you will need to put in to build a successful second income stream.

I know the internet is full of sales letters telling you that you can easily make an income of $500, $5000 or $50,000 a month but the reality is that unless you are prepared to put in a significant amount of time finding a market, identifying their needs and then giving them real value, you won't make any money online. Plus you will need to spend a significant amount of time marketing your website.

Building a business takes work - always more than you think at first. Yes, anyone can do it provided they get the fundamentals right, but that doesn't mean it is easy.

I don't want to be a wet blanket - and I am prepared to be told I am wrong - but I don't think you are going to get very far with just putting up a website and trying to sell other people's content unless you either build a significant online community or spend a lot of time marketing.

Tony, if you aim to make a site that only earns $500 per month you are looking at either the following:

1. A site where you are lucky, has popularity, and you earn near that in ad revenue. Look at the buysellads.com marketplace to see how much other sites are charging for display ads. You can quickly see it does not take much in popularity to make the $500.
2. A site that is limited, which will probably phase out over time.

You might want to consider this:
find a good affiliate program that you are comfortable selling
For example, Godaddy, or vonage, or ....

Then invest your time in a bit of research.
Do some test posts, and ads, to see if the affilate program generates revenue.

One of the best examples of Affiliate program income i saw was when searching for a Virtual PBX system for my new office.

I found a review site that reviewed 10 of the top players.
The reviews seemed fair and legit,
What i realized upon close inspection was that the reviews with links to sites where there was no affiliate program were greatly skewed (poor), and the reviews for sites with the highest payouts were very high.

The publisher of the site was not providing honest reviews, rather solidifying his position that you should subscribe to the service that was most profitable for him.

You probably dont want to do a "Fake review site"
But you can do something like that related to a niche.

You can do a review site for
Compare SSL Certifcates.
Link customers back to Godaddy, Verisign, Etc.

you can do a review site for Compare merchant rates
Link customers back to Paysimple, paypal, etc.

If you focus on niches like the one above you will quickly understand your market.
Invest the time to make sure the content of your site is of proper value.

The sky is the limit on the niches you can take on, but do them one at a time.

For affiliate programs look at commission junction, linkshare, and webmaster forums where webmasters talk about different affiliate programs that work best for them.

Best of luck.
Id like to see you make a lot more than $500 per month. How about $500 per day?