What is an I-71 compliant company?

Initiative-71 was passed in November of 2014 allowing adults 21+ to possess small amounts of marijuana legally in DC. It is still illegal to directly exchange money for cannabis, but under its guidelines you can gift flower and its derivatives to another adult. This gifting clause has led to somewhat of a work around where legal companies will sell you their goods and services, and, as a marketing incentive, give you a free gift of cannabis, similar to other companies offering free samples to incentivize customers to return.