Someone asked me this question on social media, so I decided to create a blog post about this topic.
I had a client that was ranking really well on the sub-domain, which was the company’s blog and not so much on the root domain. The blog was ranking more than the actual root domain and that was because more valuable resources were placed on the blog than on the main site. To answer your question: It does not affect your rankings per se, but I would make sure to be clear about the following:
Your Goals and Objectives
Be clear what your business main goals or objectives are. Is it selling a particular product an important ROI for your business? Is this product located on your root domain or your sub-domain? If it is in your sub-domain, then ranking there more than your root domain is great. However, if you main objective (say selling that product) is on your home page, and you are doing great in a sub-domain where your product is not listed, then that is a conflict of interest that can affect your goal (sell the product).
Conversely, If you main objective is to raise awareness of your new brand or product and nothing else, then it doesn’t matter what ranks better, as long as your brand’s message and logo are being exposed and metrics are put in place to monitor success.
Add Value
If you want your root domain to be ranking as well as your sub-domain, you would need to continue adding as much value to your root domain page as you do with a sub-domain. Perhaps, you could offer free tools and/or free downloads to an ebook, workshop videos, or weekly or daily reports or statistics to your root-domain’s page.
Canonical Tags
You want to be careful not to have many duplicated content ( same text on your sub-domain and main domain) because then you could encounter a canonical problem, so in this case, it is recommended to include Canonical URL Tag attribute to let Google know which page is the “preferred” one. The canonical tag–from an SEO perspective– is similar to a 301 redirect . In essence, the tag tells the engines that multiple pages should be considered as one (which a 301 does), without actually redirecting visitors to the new URL, just the bot.
NOTE: WordPress has a problem with generating duplicate URLs versions of the same blog post, which can cause confusing for the search engines and can effect your rank. To solve this use the Categorize parameters with the URL Parameters tool. Also learn more about Managing URLs with multiple parameters. Lastly, to learn more about the impact of duplicate URLs read google’s information about it.
At the end of the day, ask yourself: what is your unique selling proposition (USP)? Be clear about what key business objectives and goals are most important to your organization’s goal, so you can allocate resources to rank well for those.
Resources you could use:
How to set up SMART Goals. This is for Social Media, but it can apply to any marketing activity.