In niche finding => what's the minimum search monthly volume I should consider?

I'd love to hear some advices.

There should be a minimum if you don't have multiple streams of income because you have to consider the conversion rate.. and if you are only getting at most 3,000 visitors a month (if you are ranked and can get them to click on your link) that would not be very profitable.

Ideally you want a keyword with mid to high search numbers and up with low to mid competition and learn about seo and how to drive traffic to your site

I have seen at least 10 different selection methods for minimums. Bottom line is this, you need enough traffic to make that web site worth making. Nice answer, eh?

If you are targeting micro-niches with mini-sites, a very low number of searches (1,000-3,000) can pay off if there is little competition and a decent payout for sales.

If you are targeting a bigger niche with lots of competition, you will need a really good strategy to get traffic. But, you can make good money off of even small portions of traffic in a big niche like weight loss or acne.

So, my calculations are something like this - the longer it takes to create a site and get it ranked, the more traffic that niche needs to have. I have a few sites with less than 1,000 searches a month that get me good traffic because no one else is targeting them and they rank well. I have other sites that are long-term moneymakers that are slowly climbing the SERPS and have huge competition and traffic. In the mean time, they are bringing in a decent amount of money simply from the fact that there is a lot of traffic to be had.