1) Give information about your activity to your community
At first, having a blog allows you to stay in touch with your community by keeping them informed of all the news you have within your company. Many opportunities will allow you to create new content as a new product or service, events you organize or signing a partnership for example. All the reasons are valid in order to produce content and thus strengthen the relationship you have with your prospect or customer.
You can also share your articles on the social networks that your company uses or in a newsletter to increase the traffic on your website.
 

2) Position yourself as an expert
Publishing content is excellent for your reputation on the web (e-reputation for intimate). When you are going to produce used content to your readers you will prove to your community that you are expert in your field and therefore give you legitimacy on your business.
No matter what activity you do, you must have knowledge that can be useful to your readers.
Beware, however, of not leaving your field of competence at the risk of losing your community on the interest that you can bring it.

3) Improve your visibility
This point is extremely important. Indeed, you probably know that google does a ranking of websites according to the content it contains. The ultimate goal is to optimize the user's search so that he can find the answer to his search as quickly as possible.
The more you will produce content related to your activity, the better your SEO will be (and therefore free) on google.
But you will tell us that visibility does not stop with the search engines and you are right!!
By sharing your articles on social networks, you will show your communities your knowledge and expertise. We're talking about Facebook, Twitter, professional networks like Linkedin and forums/groups that you can find on different social networks. This will allow you to have a strong exposure at lower cost. 
The ultimate goal is to attract more people to your website. Therefore, google can give you more visibility since your traffic and your content interests the community.

4) Dynamizing your marketing
Content marketing is the great trend of the moment. The goal is to generate interest (and therefore traffic on your website) through useful or fun content. Beware, this type of marketing does not have the primary purpose of inciting to act or buy your product for example.
Companies can then capture prospects without going through the conventional advertising channels that are generally paying and expensive!

5) Earn money
We could not talk to you about a blog without discussing the financial aspect of the thing. Indeed, if the community that consults your blog grown up, you can make money !!
How do we do that?
Whether you want to expand your customer base, start partnerships with other bloggers, promote third-party articles on your blog, or do freelance writing for other companies, you'll quickly see New opportunities to offer yourself. Obviously, the possibilities may vary depending on the nature of your activity and the size of your blog. Nevertheless, with a little technique, it is very likely that you manage to monetize your efforts.