I recommend Everyone with a business install WordPress in Multi-Site mode.
You might think you only need one blog. You definitely should focus on a single business at a time, and I bet you will find good ways to use multiple WordPress sites.
If you are a good writer, each book you write would have a blog specific to the book, and the questions people have about the book, and how they’ve used what they learned.
Or you could market to different groups of your customers. Let’s say you have a course or coaching for single parents. Maybe marketing separately to single moms and single dads would be more effective, or maybe some things you offer would be best marketed to both. The only way to know is to Test, find out what actually works better. The best marketers know that what they think will work is rarely what actually works; they write ads and sales letters that use their knowledge of what makes a good ad, write many of them that each could work well, and let the people tell them which ads are best by responding to the ads.
Place the same marketing letter on all relevant blogs and place ads that alternate sending people to each of the blogs (e.g. sending an ad for women to the “single parent” site and the “single mom” site). (That is called “split testing”, one ad sends people to page A, ad with “something different”, perhaps a different headline or slightly different offer, sends people to page B; track which page gets more viewers, more sales, more money per sale, or more repeat customers.)
Another reason for having multiple blogs is multiple groups of people might be interested in the same workshop or coaching or products, if you speak specifically to them. Maybe slightly different age groups, or education levels, or income levels, respond to slightly different offers. Maybe people who are brand new to what you teach want a different style of marketing than people who have learned some about it already.
If you have specialty items, but your customers sometimes come to you to solve their more “commodity” problems, (and if it would be minimal work for you to have basically another business) you could offer that. Lets say you supply specialty cakes to restaurants, but the restaurants sometimes get requests for banquet food, larger orders than you could handle, and less expensive cakes than you provide. You know of another company that you could recommend. Instead of just passing the customer to the other company, you could have a separate blog to promote the products or services you don’t take care of directly, you are an affiliate or receive a referral bonus from a business that takes care of those requests. Having the separate blog lets you keep each blog focused only on the one customer, always better than trying to take care of everyone. Put a small ad on each blog, mentioning the other; customers who find one can pick which “company” is a better match for what they need.
The installation for WordPress Multi-Site is detailed, but you would only do it once. The first benefit of WordPress Multi-Site is you would only ever install WordPress that single time; no installing the WordPress program, plugins, themes multiple times; no configuring each of those multiple times. That saves a lot of administrative work. I can install WordPress for you from scratch, or convert a single WordPress installation to WordPress Multi-Site. (Migrating multiple single WordPress installations into one WordPress Multi-Site installation, each blog looking exactly like it did, is also possible, more complex, yet I can do it for you too, very few people know how.)
