So ... Let's see the first tip ...
1. The niche itself
The truth is that certain SEO-related factors should be considered even before settling down to a specific affiliate niche.
There are 3 factors here ...
1.1 You need to be specific
No matter what niche are you going to choose, you'll want to target a specific audience. And no matter what niche are you going to choose, you won't be able to cover the whole "industry".
This is why we are saying that "the narrower, the better" ... Are you interested in fashion? Great! But wait! Men? Women? Clothing? Accessories? Etc ...
The point: your very first niche idea usually can be divided into narrower sub-topics and the more specific you are, the better.
1.2 You need traffic
Once you've selected the most exciting segment, you'll have to check it's traffic potential!
The best way to do this: make a list with your most relevant niche-keywords and find out if they can generate substantial traffic volumes or not. With Jaaxy is a simple walk in the park ...
More than that, if you are planning to target multiple niche segments or your niche is still a bit "broad", you can create semantic keyword groups for each segment. This way you can analyze the individual traffic potential for each target group.
1.3 You need a "countervailable" competition
You can't outrank well-established powerful brands. So, don't start a David & Goliath fight ...
The point: you'll have to check the severity of our niches' competition at the very beginning.
Conclusion
You'll have to carefully weigh the pros and cons for every option.
Your goal is to find the perfect fit for your business type, and more importantly, the best fit for the available amount of resources you have (time, knowledge, money, etc).
Here are a few tips that will help you to find the perfect fit:
https://my.wealthyaffiliate.com/training/how-to-choose-the-p...
Regarding the affiliate links as I give the feature "no follow". Thanks for the clarification.
Claudio