Advisor shares compensate advisors for ongoing strategic, technical, or commercial help. The Founder/Advisor Standard Template (FAST) from Founder Institute is a common framework: advisors receive 0.1% to 1% depending on role and time commitment, vesting monthly over 1 to 2 years (no cliff is the norm).
Formal advisor agreements clarify deliverables, time commitment, and termination terms. Without one, advisor relationships often drift into informal arrangements that lead to cap-table problems later.