of a fee is not reasonably assured, we defer the fee and recognize revenue at the time collection becomes reasonably assured, which is generally upon receipt of payment.

 

Our policy on sales to certain distributors with rights of return is to defer recognition of revenue and related cost of revenue until the distributors resell the product, as the level of returns cannot be reasonably estimated.



Our customer programs primarily involve rebates, which are designed to serve as sales incentives to resellers of our products in various target markets. We account for rebates as a reduction of revenue and accrue for 100% of the potential rebates and do not apply a breakage factor. While we have a long history of rebate arrangements with OEMs, we believe we are unable to apply our historical experience to reliably estimate the amount of rebates that will eventually be claimed by individual OEMs. The OEMs are not our direct customers and the quantity and mix of demand they place on CEM/ODMs may shift as we introduce new generations and iterations of products and as we experience changes in new competitor offerings. In addition, we typically find that approximately 95% of the rebates we accrue each year are eventually claimed, which is substantially close to 100%, and that this percentage varies by program and by customer. We recognize a liability for these rebates at the later of the date at which we record the related revenue or the date at which we offer the rebate. Rebates typically expire six months from the date of the original sale, unless we reasonably believe that the customer intends to claim the rebate. Unclaimed rebates are reversed to revenue, the amount of which typically represents approximately 0.5% of total revenue.

 

Our customer programs also include marketing development funds, or MDFs.  MDFs represent monies paid to retailers, system builders, original equipment manufacturers, or OEMs, distributors and add-in card partners that are earmarked for market segment development and expansion and typically are designed to support our partners’ activities while also promoting NVIDIA products. Depending on market conditions, we may take actions to increase amounts offered under customer programs, possibly resulting in an incremental reduction of revenue at the time such programs are offered. We account for MDFs as a reduction of revenue and apply a breakage factor to certain types of MDF program accruals for which we believe we can make a reasonable and reliable estimate of the amount that will ultimately be unclaimed. MDF amounts that have been previously recorded against revenue and subsequently expired unclaimed are reversed to revenue. Such amounts have not been significant.



We also record a reduction to revenue by establishing a sales return allowance for estimated product returns at the time revenue is recognized, based primarily on historical return rates. However, if product returns for a particular fiscal period exceed historical return rates we may determine that additional sales return allowances are required to properly reflect our estimated exposure for product returns.



License and Development Revenue

 

For