Or more accurately:

Create
Read
Update
Delete

>>>We rebuild indexes daily, but we have a fair amount of CRUD.
>>
>>What is CRUD?
>>
>>>Don't forget about reorganizing indexes. Fragmentation greater than 10% but less than 30% (IIRC) suggests that index be reorganized rather than rebuilt. SQL Server can reorganize indexes without making them inaccessible which means no down time, though I would recommend doing reorgs during off-peak hours.
>>
>>I never rebuilt. I delete them and recreate them from scratch.
>>
>>>SQL Server Enterprise allows rebuilding of indexes while leaving them online for 24/7/365 uptime goals.
>>
>>What do you mean exactly?
>
>CRUD - insert/update/delete operations.