If i purchase several domain names all related to my niche and just point the DNS settings to my one site will this hurt my serps with google? I know that if I had my site cloned on each domain it would. But I will only have my one site with the domains pointing to it.
It is effective to a great extent, you should include keywords in domain name and even in the inner URL pages.
I've been doing that and haven't really noticed any positive effect on my SERPS tbh. Might just be down to the fact that most of the sites are very new though and have no authority.
i believe it it won't if you do forwarding, you'll get the traffic but i don't see how it'll improve your SERPs.