Newbie Question

Hello, i need to know WHY i need to have a niche for affiliate marketing. Would a general product review website be possible. What if i make categories and out the reviews in categories? I just need to know the reason to have my website within a niche, thank you.

I m new to IM and I just started to read around here. I m not sure of my answer but maybe it's because it's very hard to drive traffic from a general place to ur website with various products.
But if u pick a niche an promote ur website in forums of ur niche it will be easier. Someone correct me if I m wrong

make categories to make review the categories that would be better

If you have a broad niche, you will get more traffic but it simply won't convert. Traffic won't be targeted, and if it's not targeted, normally conversion rates are much lower.

If you write about one particular niche with a good product - you will attract perhaps less people, but they will be interested in the product and will more likely buy it. It's just much more simple and more profitable than trying to catch someone who would be interested in a broad audience.