Conversation so far:
How were Drake's early mix tapes distributed?
Drake self-released his debut mixtape
How many copies of Drake self-released his debut mixtape sold?
Drake's mixtape was released for sale only, and confirmed to have sold over 6,000 copies
When did Drake create his next mix tape after his self-released debut mixtape?
In 2007, Drake released his second mixtape, Comeback Season.
Did Drake's second mixtape, Comeback Season sell better than his first tape?
Which single from Comeback Season was featured on BET before Drake was signed with a label?
Replacement Girl. The song made Drake become the first ever unsigned Canadian rapper to have his music video featured on BET

Question: When did he sign with a label?
Self-contained rewrite: When did Drake sign with a label?