I just received a contract from Tesla last week with the following wording:
TAXATION OF POWERWALL AWARD AND W-9 REQUIREMENT. As a reward for your referrals of Tesla products, Tesla will provide you with a Powerwall (value $6,700 USD) and a Backup Gateway (value $1,100 USD) at no charge, along with an installation credit of up to $1,000 USD. This award will be taxable income for many of our customers, including customers who are citizens and/or residents of the United States. The award may be taxable income for state income tax purposes, as well. Tesla is required to report such income to you and to the Internal Revenue Service (IRS) on a Form 1099-MISC. Thus, you will need to provide Tesla with your U.S. taxpayer identification number on a Form W-9. By entering into this agreement, you agree to provide Tesla with this Form W-9. Tesla will contact you to request the Form W-9 from you.
I assume this has been posted before, but it seems clear what they consider the taxation value of this referral award to be. Since this is a contract it would be be a little strange to then put different values on a 1099. But, considering nobody has actually seen a 1099 from Tesla, who knows...