After reading this weeks post you're probably going to want to refer to me as Professor Stickler, but I'm ok with that because right is right.
Building or creating a logo in Adobe Photoshop is wrong. Before I go into the specifics of why I will give you a moment to consider the reasoning for this yourself. If you have been following these posts on Monday mornings you have enough info to figure this out, let's see if you've been paying attention.
Got the answer yet? Think for a moment, I know you can get it.
The answer lies in the difference between bitmap and vector art files. Photoshop is a bitmap program which limits the usability of your logo. Admittedly Photoshop has become a lot more handy in the last few versions imitating some vector functionalities, but it still isn't Adobe Illustrator.
Technically you could get away with building your logo in Photoshop in a lot of instances. This is especially true if you're primarily a web-based operation. After all, most web graphics are created/assembled in Photoshop so why can't the logo be part of that? Well it can. When I'm making a site, I open my logo in Illustrator, then copy and paste it into Photoshop.
But if there comes a time when I need to do something for print I have that same logo from Illustrator and work with it in my print file. Now again, this could be accomplished with Photoshop if you made your logo large enough and at 300dpi, but chances are not too many people are going to do that. On a side-note, creating a logo in Photoshop creates the temptation to do to many complex tricks with their logo using filters or other intricate things that shouldn't be done in logo design.
Suppose furthermore that at some point you need to create some promo material and the production company asks for a vector file because that is all they work with. Now you're in a bind and may be facing time constraints to solve this problem or additional costs.
Lastly, an Illustrator file can be easily made into any bitmap format but Photoshop doesn't translate into vector so well. There are some techniques, but they are not super reliable. Illustrator is completely universal so that is why I hold to the position that all logos should be created in Illustrator.
The last thing I want to share is the thought that owning proper files and having them organized is a key component to managing your brand. I continue to be surprised how many organizations do not have proper logo files or images that are integral parts of their brand. If reading that sentence hurt in any way, it might be an indicator that you have a pretty important item to put on your to-do list. It might not seem important now, but it's the kind of thing that can sneak up and hurt you later.