build content site? or affiliate site? like amazon's web site. I have seen some amazon affiliate sites around. don't know how to attract traffic to affiliate site.
content websites. especially if you have decent traffic. you'll se way more profit than from affiliate sites.
Any site has potential of making money if you put enough time and effort into it. That said I'd reckon Amazon affiliate sites aren't really worth it due to the competition. There are so many sites out there already... IMO a content site is a great route to take. Build a site with rich content, build links to get traffic and update regularly (the part I always fail to do ). You could monetize the site by placing Google AdSense on it and also affiliate links to related products (e.g. guitar equipment sales if you run a guitar lesson site). Also if you manage to write useful content and come across to the visitors as you know what you're talking about, affiliate sales will become a lot easier. You could write helpful reviews about each product to increase affiliate sales as well.
If you have no money for advertising, content site is your only viable option. You can rely on search engines and inbound links for traffic. A site that is build purely to sell something requires money to bring in visitors, as no search engine is going to list your contentless site any higher than, say, page 5,000,100,100. If you're lucky.
I'm not sure I understand your question, but whether you build a site to make revenue from Google Adsense or from affiliate programs, the site has to have good content. Furthermore, a site with good content can do BOTH at the same time. Google TOS doesn't prohibit affiliate programs.
Making money from either type of site is possible. It's all about traffic though - if you can drive traffic to any type of money making site then you'll profit. The question is, do you have the determination *after* the site is complete to spend a *lot* of time building up traffic? (Link building, directory submissions etc..)
Content sites are your best bet for long-term income. There are too many of those Amazon sites that all look the same. With content, you can find a good niche where your site will stand out.