Heres how I come up with new niche ideas:
Step one: Use this tool to check out the traffic of different keywords.
Step two: Once you've found one check the serps.
Step three: Once you've taken a look at the competition you going to want to analyze their sites. You can use many tools but I think looking at the standard stuff gives you a good idea of what it would take to beat them. Here are some examples:
- domain age
- quality of the site
- How significant to the keyword is the site
- this is the most important factor IMO: backlinks with anchor text. You can use this tool to check.
I won't give out all of my secrets but really use the first tool and check out different niches. Use your imagination and set goals that you can achieve. In the end you will get traffic for your content. You could easily outgrow your niche. This site is about "Mac poker" but it dominates the serps for a lot of good poker terms.
Hope I helped
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p.s. I don't want to get criticized by anyone for giving out bad advice. Everything I wrote is just my opinion and I could have left something out or just simply be 100% wrong.