Bluehost Addon Domains Question

[jyzackoh]

Hi guys,

I currently started using bluehost for my webhosting and I just realised that when they meant "host unlimited domains", the new domains were just considered add-on domains.

And this means the addon domain is just pointing to a sub-domain of my primary domain or something like that. Would this affect my SEO rankings? Cos like if google's spiders crawl my primary domain, won't it crawl my subdomain too? Then there will be "duplicates".

Anyone can enlighten me about this issue? Oh and is hostgator's "host unlimited domains" plan like this as well?

Thank you so much!