Looking for Advice on Affiliate Marketing

Hi all,

I consider myself somewhat of a successful affiliate marketer, but always want to improve what I do and hopefully someday make a little more money doing this.

I run a couple of sites right now where I have a general theme, and then create various Wordpress posts centered around the domain name. They are generally low searches, but low competition so I have an easy time getting onto the first page. I would say with my main site right now I make about $10/day. Don't get me wrong i'm happy with that, but i'd like to get that up higher.

I tried a couple of other sites, but have not had the greatest time getting them ranked higher. I think I chose some keywords that are not searches for very much and think I need to re-evaluate what i'm doing.

Here are a few questions:
1 - Are most people just setting up a simple landing page based on high number of searches/low competition for a keyword, writing a detailed article, and hoping someone will click on the link? I have a tough time wrapping my head around purchasing a domain for 1 product, instead of multiple products. One thread that caught my interest the other day was where someone mentioned they made $1000 in a day on a particular sale. Quite a few people in the thread asked for who the merchant was and mentioned that they would have to use them as well. Again, are these people mainly looking just to set up a single page on a domain?

2 - Is the Google Adwords keyword tool Exact searches the best approximation for # searches? My 3rd site (which isn't doing well) has multiple broad searches of 2,000 (monthly) searches. But exact the numbers are somewhere around 50-100. I know this is a poor number but when you have 100s of posts, I thought it would help.

Anyways just looking for a little more advice about what others are doing in their affiliate marketing endevours.

Thank you everyone!