Is there a point to vanity addresses if a new destination address should be created per sender? There is some advice for merchants to have a unique Bitcoin address for each incoming address.    Apparently this will help associate a transaction with a sender.

Since it can take a long time to generate a vanity address:


Is there any benefit to doing this if one should be created per sender?
When does it make sense to use a vanity address?
Vanity address' purpose is generally in its name - vanity. You mainly use it to show off, like say in forum's signatures or general donation address, not for business in most cases. Usually you won't want to use a vanity address when you want to remain anonymous, which is what you try to accomplish by using a new address for each transaction. You can use the vanity address to mark your brand as well. For example, SatoshiDice's addresses all start with "1Dice".

Generally, you would use a vanity address if you can spare the computational power where people could see it quite clearly, and use the other addresses when you don't want to make an effort.