Disadvantages to using /%post_id%/ as permalink structure

Hi all,

I want to make my permalinks as short as possible – I’m going to be handing them out on business cards and the easier they are to type, the more hits I’ll get.

Right now, I’m using Custom Structure with only /%post_id%/.

This means that I can give people links to website.com/39 and they’ll find the right post.

Are there any disadvantages to doing this? I’m aware that using only post-name or category can be problematic (load times), but are there any problems using only /%post_id%/?

Thanks!