You don’t want to bite off more than you can chew… this guide will help you decide if dominating your niche is realistic.
Check Your Competition
For your keywords, get some idea of your competition. I typically do this using Market Samurai but I also just like to take a look at the Google search results and figure out for myself. You can generally judge by the quality of the top 10 results, number of Google Ads, number of results etc.
Try and filter down your keywords to those that are feasible to target (i.e. little competition). Of course, if you have a big budget for SEO or PPC then you can target what you like (just make sure the Amazon commissions are worth it!).
What to Look Out For in Your Competition
How do you know if your competition is any good? Look out for how professional the site is, if it is a real store or an affiliate store, what the Pagerank is and how many backlinks the site has.
You Can Still Beat the Competition
The more competition, the more work it will take to get up the search listings – but it is still doable. Just consider how much time you can put into it and how long before you need to see results.
Once you are set on your keywords and niche, move on to the next step and choose a domain.