What's the difference between creating a category for just a specific product/service vs. for the entire company? (Micro vs Macro category creation)

I don’t see a difference actually, at least for technology companies. At the end of the day, customers don’t want your product, they want outcomes that your product (and company) help them derive.

Few examples:
• Uber/Lyft sell the ability to get from point A to point B without a car. The app is just a vehicle (pun intended).
• AirBnB sells the ability to belong / feel at home anywhere in the world.
• Etc.

Start by deeply understanding your persona and work backwards from there. Understand the jobs they’re looking to tackle and how your product and company both have a role to play in concert with each other.

I don't think there's a significant difference. Ultimately, creating a category is about:

• Identifying a customer problem

• Reframing the way they think about it

• Presenting them with a fundamentally different and more compelling way of solving that problem.

The fundamental goals are the same, regardless of the level at which the work is done. That said, I do think it can look different depending on where a company is in their evolution. For example:

• Phase 1: Initially, a company may start its category creation journey by trying to create a category for an individual product.

• Phase 2: As they grow into a multi-product company, they may end up participating in multiple categories that correspond with each product they build and sell.

• Phase 3: Over time, the company might seek to create a new overarching category that includes the existing categories as sub-categories.

• Phase 4: Eventually, the overarching category may subsume the individual product categories so they become less relevant or cease to exist.

I think you can see an evolution like this taking place in the marketing space where companies like Salesforce and Oracle have developed Marketing Clouds that include sub-categories like ESPs and social media marketing tools that were once standalone categories but have been absorbed by the larger Marketing Cloud category.

At the end of the day, I think the work you're doing is pretty much the same, just applied differently.

• A micro category is relevant for specific product/service as it provides a niche use case that the offering supports. 
• A macro category for a company is the high-level category that aligns with customer needs and expectations in the industry.

Both micro and macro categories co-exist and it’s crucial to help teams understand the dimensions needed for both categories. Macro category can have breadth while a micro category needs more depth. 

Eg: If the macro category is Integration Platform as a Service (iPaaS); a micro category could be Application and Data Integration, API Management etc.