The Categorical HubSpot

Links to the complete collection of HubSpot products, ecosystems, and resources.

Ecosystem

We didn't talk about the Academy, but (in my opinion) it is the single greatest value-add that HubSpot offers.  The new business that comes in from people signing up for Academy courses / downloading resources is gargantuan.  Completely free and would be worth checking out as a sales leads source or engagement amplifier.
Forum-style, notable in that it's very active with employees, customers, and trial users.

Freemium Product: CRM

The Free CRM for Small to Enterprise Businesses | HubSpot- HubSpot's CRM is considered the "master" in terms of its database of Contacts, Companies, etc. - All other HubSpot tools (those within the Paid Marketing, Sales, Service, and IT categories) align and automatically enrich the CRM data with their respective analytics and tracking tools. - Freemium, so expect ads :\

Partnerships and Other Programs

Provides an overview (with links to dedicated pages) of HubSpot's various affiliate, revenue share, and Partnership programs.

Onboarding

HubSpot | Onboarding Services- Not sure how far along Rally is with developing the customer onboarding, but this could be useful from a framework standpoint.

Products and Outcomes

Power of the Contact Record- Very helpful visualization on the "core" of HubSpot -- the Contact Record - Helps explain why HubSpot's pricing is based on number of Contact Records in your system

HubSpot Product & Services Catalog- Complete listing of HubSpot tools, categorized (by pricing package) with short descriptions.

Co-Development and Integrations

App Marketplace | HubSpot

HubSpot Developer Site

The 13 Best ERP Apps for HubSpot - HubSpot App Marketplace