Andrew Allemann has a great post on Domain Name Wire where he tries to estimate the impact of GoDaddy’s five-year default domain name registration option.

GoDaddy’s shopping cart defaults to a five-year registration period when you place a domain name in your cart. Most people switch this back to just one year, but some don’t. Whether they merely overlook this or decide it makes sense to register the domain name for five years, about 3.5% of new .com registrations at GoDaddy each month are for five years.

Here’s a summary of the math:

• In June, the .com registry reflects 26,750 five-year registrations which account for 3.48% of all their .com registrations so 26,750/.0348 = 769K total.
• On average across all registries, only 1.66% of of new .com registrations are for 5 years.
• Had GoDaddy met the average, it would have only registered 769K * 1.66% = ~12,750 five year registrations.
• That works out to be a difference of 26,750 – 12,750 = 14K five year registrations or 14K * 5 = 70K years of registrations.
• Assuming those users would have purchased 1 year registrations if 5 wasn’t the default, that works out to be 70K – 14K = 56K extra years of registrations per month thanks to that five-year default.

Regardless of how you feel about GoDaddy, you’ve got to admit that they’re really effective at upselling.

Hattip to my coworker Wendy for sharing the post.