The logo has to reflect the personality of the company it represents. It will usually be the first thing anyone will come across that will be associated with the company, person, etc, you understand - the first impression-no 2nd chance to make first impression? Also, your logo needs to catch the mind, the imagination of the viewer. You want people to remember what they have seen. What they have seen today, yesterday, and a month from now when they see it again you want them to put logo and product together. Your logo can be your public face. It also needs to somehow incorporate the mission statement of your company, proprietorship,whatever you are selling from,in my opinion.
Mission statement, product, personality ,who you are(face) and durability.Hey try to put some lifestyle into it too.
I would also suggest to you to study what effect, types of language usage, has on study groups and also what effect the stylization of letters convey to study groups also. You should know the rest .Hope I was helpful. Unless you're just making bumper stickers.