For the website of a manufacturing company that markets to both B2B and B2C, my team is creating a "Professionals" section to provide resources to the professional markets that we serve. (Our website is primarily consumer-focused.) There are 6-7 different professional groups, each with a very different personality and set of needs. We are going to create a target section for each profession, but we are struggling to know how to get the professional to their section.
Some of the ideas that we have considered:
What would be considered best practices for a site or sites trying to target several different categories of users?
The last option you mentioned "A completely separate, professional-focused website" would seem the least desirable, as it would not be very flexible/scalable in response to additional professional categories being identified in the future.
A "modal" on a web site does not seem like good practice.
A combination of the remainder of what you suggested may be satisfactory. i.e. both common (with sidebar) and specifically marketed "landing pages". You probably want the sidebar filled dynamically, if, that is, you add/modify professional categories frequently.
As one additional thing that you didn't mention... If some of your professional categories are "general" or not so obvious to select, you might provide a series of questions to help the user select their desired category.
1. Same B2C product with small customizations / a few additional features for B2B - Provide menu on the same page.
I guess this is what you are looking for. I have also provided two other business scenarios.
2. Same product but more features/ extensive tool kit / premiere services - A link on home page that redirects to professionals/Business page
3. When the B2B side have to interact differently from B2C or to generate and manage their own content or access analytics, etc - Provide a different url
Your IA choice depends on how different the product and the experience is for B2B and B2C customers.