I've done it again; a new comic for your perusal. Logo Logic is about branding for your website and beyond. The fact is, whether you hire me or not, you need a logo for your business, or at least for your website. Logos provide a professional touch that makes your business stand out from the crowd.
A good logo is clearly visible at different sizes, is distinctive enough to be recognisable, and the image file should be either .png or .bmp at 300dpi to avoid the distortions you get with .jpg or .gif files. Mascots are good and help to build the brand but they're not obligatory.
Text-only logos are perfectly acceptable but you need to be consistent when using them.
Trademarking isn't really necessary unless you've got a major brand and you're concerned about people impersonating you or trying to profit off your image. In any case, prior art applies so if you do decide to trademark your logo, make sure it's not too similar to anyone else's, particularly if you're in the same business.
Trademarking a text-only logo can be problematic unless you've created the font you're using for it. I'm not an authority on copyright law, and in any case I'm campaigning for copyright and IPR law reform because of the problems that ensue when the laws are so tight that they restrict what people can do with colours and shapes, etc., so be sure to do some research before you decide on whether or not it's worth trademarking or copyrighting anything. Personally, I don't bother and it's not done me any harm.
Enjoy the comic! As ever, it's free to share as long as you cite and link me when you do, and don't try to pass it off as your own work.