Will you get penalized by google if you own the same domain name with a different extension like the .com and .net but have the same content on each of those domains?
You will most likely not get penalized, but both sites will probably not rank, and it is possible they both could get downgraded if the search engines are unable to identify which is the original source. Is there a reason why you want to maintain both sites, and not just redirect one of them to the other.
I can't think of a reason to have both host content if they are both the exact same content. Why not just redirect one to the other?
I have a domain name I really like, but its in the .ca extension(I'm Canadian), but I read that google will only rank that domain good in canada, while other extensions like .com will rank good internationally. So I added the word "the" to the domain, and the .net is available. So I am thinking of using that domain, and redirecting canadiens to the .ca, and eventually trying to buy out the other domains without "the" in the domain.
if both site have same content then you 301 redirect to one of those website you don't need to operate multiple website for one service
Hopefully this video from Matt Cutts will help share a little more light on it. http://blog.buildawebsitetonight.co...nt-posted-under-different-tlds-a-problem.html
Definitely if you have same domain with different extension with same content. However, if you targeting different country and same content with different languages for example one is with Spanish and other is with English then in that case you will be not penalized.
yes there is a chance of getting penalized by google due to duplicate content issue or mirror site issue.