It is important to standout above the rest loud and proud.
When you try to tell a story about a company purely through logo, you will inevitably fail — there's simply not enough room or a proper way to tell everything there is to be told. It's like asking a CD cover to sing you a song… it simply doesn't work.
A logo is an expression of a company's identity — the things that matter and have meaning to the company. As such, it's perhaps the only commercial device which isn't intended to boost sales, but provide a form of identification and a source of pride to company owners and employees. However, this is not to say that logos should not carry symbols. Sometimes a symbol can become more memorable and ubiquitous than the company name itself, such is the case of Apple, Nike or Pepsi. Other times, a symbol is just a hindrance, a superfluous decoration which doesn’t really add value or meaning – such as the semitransparent blue square in the late GAP logo. The lesson: use a symbol if you need to represent something important to the company. If not, it’s best to consider more typographical solutions.
You may not be happy with the answer but here it is: it depends.
It depends on who the client is, what their history is and where they’re trying to go. Are they a market newcomer trying to grab attention? Are they an established business seeking to show some tradition? Or maybe they’ve been out there for decades and need just a quick face lift.
Just like a signature, a logo is entirely about the person behind the signature, and very little about the person receiving it.
Keep that in mind, and you’ll do well.