You might be wondering if it's worth it to do a guest post.
The answer is yes.
There have been reasons to do a guest blog post since before black hat SEO started ruining the concept, so good riddance to that rubbish. Forthwith, some reasons to do a guest blog post.
Two months ago you launched a new product that was 6 months in the making. Adoption was good, but not so outstanding that you can release some user numbers. The next product release won't be for another 6-9 months and you're afraid that you are losing a little momentum in the marketplace. Since a news article is unlikely, hit up a target publication as a way to keep in the forefront of your prospective users/investors.
Are you trying to establish your company in a crowded niche? Maybe trying to create a niche where this is none? Writing a guest blog brings more credibility than a post on your own blog and helps to support you as a thought leader in your space. Be sure that the blog topic aligns well with the worldview and vision of your company. A blog post about an unrelated topic is a missed opportunity.
Participating in the conversations that matter to your industry is another great benefit of a guest blog post. Sometimes it's the opportunity to ask a question of the community and spark a discussion. Or it might be the opportunity to highlight other people/companies who are doing great things. The key here is being able to build or grow a community which will help your company succeed. Guest posting is also a great way to introduce your company to a new community or explore new markets. Not sure how your product will be received in another industry? Do a guest blog post to gauge the reaction.
How to get coverage
Most blogs tend to have a submissions guidelines page. Follow their guidelines carefully and write a post that the publication will be interested in. Barron's won't publish your zen relaxation tips because it's not on their beat and unlikely to interest their readers. Fast Company has a good post on how to be a successful guest blogger.