I've been selling businesses a long time and I get many call from buyers who are open to buying something but aren't sure what would be a good investment. I'll get asked what I would buy if I was them and my answer is always the same, "a service-based business".
There are plenty of reasons for my choice but the most compelling is my aversion to risk. While its true that service businesses typically come with fewer assets than the average business I say, who cares. Maybe it makes some people feel better to walk into a business that has office equipment, machines, people doing things with the machines. I just see liability. Over the course of my professional life I have seen business equipment sell for pennies on the dollar, so I feel that if you're thinking that these assets are going to save you in a worst-case scenario then think again, that's a false sense of security. Capital equipment is a different story, but few businesses come with equipment values over a few hundred thousand dollars.
I believe in pure cash flow without the drain of appendages. When I first got into business brokering I couldn't give a virtual business away now 13 years later, I just closed a sale of a 6-million-dollar business that came with 2 laptops. Service can even be retail if you aren't responsible for a lease of space, furnishings inside, employees to run it, and sitting on inventory, thank you Amazon. The less responsibility the business has to bear the better it is. Also, the more flexible a business can be the better it is. Businesses try to control sales by doing their part, marketing sales calls etc. What about the unforeseen market circumstances that no one saw coming that have a real affect on some businesses? In a service business that doesn't have an expensive monthly lease or many W2 employees to feed, you can streamline to adjust for the change but if you're trapped in many fixed monthly expenses then you won't weather a long drought.
A service business isn't for everyone of course. If you're a machinist, then you are a machinist and that's not virtual unless you contract another machinist to do all your work for you. The point is that we need some businesses to have a storefront and warehouse, that's just how they operate. If you have a choice though and you're thinking about it, just focus on the highest cash flow and least liability.