I don't think domains are as important as they used to be, but to be on the safe side most marketers like to have their keywords in the domain name. Your above example looks fine.

Another reason is that it is easier for your customers to remember.

I would focus on using a domain for each niche and if there are sub niches you can always use a new page instead of a sub domain.

You should get a new domain.

1. It's a small cost.
2. Google consideres subdomains to be the same website.
3. Like LastWarrior said, it looks amateurish.

A good domain will always be relatively important as it will be easier to remember for your visitors if they want to revisit or to pass it on to their friends. If you are looking to pump and dump the site then it is less important but for any site you want to keep a hold of and grow over time you want a decent domain name to accompany it.

EMD or exact match domains like the one that houses my blog are not in vogue anymore but still are useful for ranking.

Better off creating a brand first and finding a domain that matches that, you can then take care of ranking afterwards. Also with a solid brand, you can leverage that through social media which Google is increasing looking through favorably esp Facebook and Youtube

If you are going to go down the emd route, you must be conservative with you're link building, you have to be careful not to over optimize with an emd

I came across this link and it talks what I am asking about.

I am not talking about using one domain with multiple sub domains for different industries. What I am talking about to pick a theme, for instance a domain like MyAwesomeReviewSite.com and then target different keywords as Subdomains e.g: ElectronicBikes.MyAwesomeReviewSite.com etc.

If the site is not important then using a subdomain is fine. If you want real traffic and plan to build a real product I would recommend giving it a unique domain.

One of the other issues with using all subdomains is that if you want to sell one of the sites, you can't really sell a subdomain.

Keeping each website as a separate "business" with its own domain makes it a lot easier to cash out eventually.

PKNerd,

You can if you want have subdomains for your other sites. The reason I have multiple sites is because for not only branding, but my end goal. I want to make sure the site name is relevant to my chosen niche. For example if I was to have a health site there are a plethora of sub niches in health right, so in this instance subdomains would work for me because I am branding my main site as a leader in my niche. Now let's say I am in the IM niche as well, and add a sub domain to my previous health niche example. Wouldn't fit right and branding would be out of alignment.

That is why I have multiple sites and the reasons behind it. For branding and establishing authority.

Id say, dont go with subcategory sub domain. youll spend a lot of time if your are installing websites on all of them. Id suggest you to have a main website for example and provide subcategories.

Thats the way i prefer for my websites. It's all up to you. Nowadays all that is not so important, just focus on giving good content and traffic will follow.

In Wordpress u can show the category along with the topic title using permalinks. Google will know how to place it.