I want to establish a PBN services which is in demand nowadays. Anyone who can recommend what are those things needed to have a services like this?
I agree, there's a lot of demand on private blog networks lately. Here's in brief how you can take advantage of that: Find premium expired domains that are powerful, relevant and free of SPAM. Build an effective PBN with no footprint. Promote your services. You can get paid whenever someone uses your PBN. Or by repeating the first two steps and building to your clients their own private blog networks. I hope this was helpful enough. Best of luck!
This is not in Demand nowadays and newbies are asking about it anywhere in the forums. It was in the demand but not now and you can't say it is Black Hat SEO technique, it is Grey Hat because it is Good for those who do it from a long time of period and keep it for that if you wanna give a try to it so put your self at risk.