Running a blog (WordPress), a forum (phpBB, Simple Machines), a CMS (Drupal, Joomla) or a wiki (WikiMedia) on the website where you run your shopping cart is something many Zen Cart users find attractive.
The problem is, these software packages don’t maintain themselves. You need to keep them updated or you run the risk of being hacked. Even if you keep them updated, sometimes plugins are compromised by bad guys to enable sites to be hacked. This is not just a theoretical risk - companies like Securi get most of their business from WordPress installations that have been hacked.
So: you can do this, many people do this, but it has a cost and you’ll need to devote more energy to maintenance and updates if you want go down this path. Proceed with caution.
Most people who deploy blogs or other tools use deployment model 2.
What are some alternative options to running a blog with your Zen Cart installation?
Create content using EZ-Pages
The Zen Cart EZ-Pages system allows you to create content using a secure, controlled facility. This content can then be displayed on your site. You can even organize your pages into chapters and have a table of contents.
Create and send a newsletter regularly
Tools like MailChimp have inexpensive offerings for small businesses that allow you to stay in touch with your customers. You can even preserve your content in a campaign archive so customers who come along after you sent it can still see it.
Use a static site generator
Static Site Generators (SSGs) like Hugo and Jekyll allow you to build a sophisticated website using a tool, and output raw HTML which can run without a database or code interpretation. Since the final output of these tools is HTML-only, it is much less risky than WordPress (which has both PHP and MySQL as potential attack surfaces).
Create a blog offsite
Really committed to a blog, are you? Instead of self-hosting a WordPress blog, why not use wordpress.com and let them host it. There are, of course, other hosted blogging services like Blogger or Tumblr.