Expansion MRR is the additional MRR that you get from your existing customers.

Expansion MRR is generated when your customer upgrade from a lower-priced plan to a higher-priced plan, purchase additional or add-ons products and reactivating a canceled subscription.

Time to value is how long it takes a new customer to realize the value they're expecting from your product or service. Optimizing for this metric will help companies grow exponentially.

There are various types of time to value like Immediate Time to Value, Time to Basic Value (TTBV), Time to Exceed Value (TTEV)

The North Star Metric is the primary metric that a company uses for its growth and it helps everyone in a company focused on one goal.  North Star Metric must lead to revenue, reflect customer value and measure growth.

Startup investor Sean Ellis has coined the term "North Star metric".

Free trial is a customer acquisition strategy that provides a partial or complete product to customer free of charge for a certain time.

Freemium model is a customer acquisition strategy that provides access to part of a  product to customer free of charge for lifetime.

Bottom-Up is  a self-serve GTM strategy
where the end-users will potentially start using  the product without any direct
involvement from a sales team.