I know a lot of people say not to build sites on products that people can easily buy at Walmart or Home Depot and that's just wrong.
1. Lots of people including me are just too lazy or just don't like going to Walmart to buy stuff. We'd much rather go to the internet and get reviews and also better prices on the product and get it delivered.
2. Hundreds of thousands of people live in more rural areas and they do the vast majority of their shopping online.
3. Lots of older people would much rather buy online and have items delivered than going out themselves to shop for them. This is especially true for larger items such as washers and dryers, furniture etc.
4. There is a much bigger variety of makes and models to choose from online than at Walmart. If you want to research and find the right product offline it often means you have to drive to 3 or more shops to see what they have. Online (Amazon) all the makes and models are right there with real customer reviews and feedback on each. Time spent researching 2 minutes vs 2 hours offline.
I can go on and on with more reasons but I am sure you get the point. People are buying just about anything online whether you can find the same item at Walmart or not so don't let that deter you from building a site around a specific product.
Another thing to think about..
I just watched a segment on CNBC about Amazon.com and their massive growth. Stock price was only $30 5 years ago vs $192 today.
They were talking about how Amazon is moving heavily into the tablet market and how they want people to keep shopping all the time by marketing to them everywhere they are. Amazon is launching a tablet they say in the next few months and I am sure there will be huge opportunities for us marketers in the app world because people will be buying hundreds of millions of dollars worth of stuff from their tablets on Amazon in the coming years.
The street is now talking about Amazon actually becoming the next Walmart in the next decade and I can certainly believe it. I believe we are in a great spot right now as Amazon affiliates so let's get creative and capitalize.