Does pedir always need an indirect object pronoun?

Does pedir always need an indirect object pronoun?
 

So ... pedir is transitive, ie. needs at least one object.

I thought that if there was an indirect object then an iop also needs be used, even when it seems redundant:

Eg. Le pidió $100 a mi amigo.

My question is - is the iop optional or not? I ask because I've definitely seen or heard a few examples of it being left out (which is to be expected I guess as there's no language where all it's speakers speak it gramatically perfectly) but then I recently came across a dictionary entry under pedir that said:

pedir algo a alguien (instead of pedirle)

Does that mean you could just as correctly say ... Pidió $100 a mi amigo? It just doesn't seem right to me, have I missed something?

Thanks in advance for any light that can be shed on the subject.

Both are correct, but the most usual is the first.
I don't know if there is a particular rule.

Preguntaré a los especialistas.
Les preguntaré a los especialistas.

(I'd use the second example, but the first is also fine...)

Y recuerda: Contra el vicio de pedir, está la virtud de no dar. ;) :D