Miland:If the meaning is 'It's as if your company were open for clients and the public 24 hours a day and in every place' one possible rendering may be

'Estas kvazaŭ via firmao estus malferma po 24-horojn tage por klientoj kaj la publikon, en ĉiuj lokoj.'

This should be with either the -n or a preposition, but not both. "malfermita 24 horojn tage" or "malfermita po 24 horoj tage" (this second variation would be rare; I would not use "po" in this context)

Fermi and malfermi are transitive verbs, so in this case, it has to be "malfermita" rather than "malferma".

Miland:'Estas kvazaŭ via firmao estus malferma po 24-horojn tage por klientoj kaj la publikon, en ĉiuj lokoj.'

And of course, "por klientoj kaj (por) la publiko", without the accusative ending.

Regarding publikon, it is indeed simpler to have one por apply to both kliento and publiko.
Helping geraldoph is certainly a greater priority than non-essential issues like po.

For my part, also, thanks for the comments, since I plan to take E-o exams in a few months, so it may be well to concentrate on uncontroversial usages for that.

geraldoph:Via firmo tra la interreto: Retejoj estas tiom pli ol gvido al varoj kaj servoj. It’s your company oppened 24 h/day in everywhere, for the people and for your clients. Also, it offers options for make easier the companies’ logistics.

"It's" should be "they're" in English. The antecedent here is "websites", which is plural, and can't logically be "internet" or "company". Maybe this will make more sense:

[LISTO]
Correct: "They (websites) are your company open 24 hr/day"
Wrong: "It (your company) is your company open 24 hr/day"
Wrong: "It (the internet) is your company open 24 hr/day"[/list]On the other hand you could just make "websites" singular ("a website"), and it would work, since "it" could then logically refer to "a website".

In fact, that would be my preference: I like "A website is so much more than a guide..." (comparing a singular to a singular), better than "Websites are so much more than a guide..." (comparing a plural to a singular).

Those were English corrections, but the same holds for Esperanto, of course. So I would translate the first two sentences thus:

Via firmao interrete: TTT-ejo estas tiom pli ol gvido al varoj kaj servoj. Ĝi estas via firmao malfermita 24 horojn ĉiutage -- kaj por la publiko kaj por viaj klientoj.

I like "kaj x kaj y" type constructions when you want to emphasize both-ness, as seems to be the case here. That's why I have an extra "kaj" in there. It's optional though.

Also, I like firmao better than firmo for "company", because I tend parse firmo as firmness. Either is acceptable though.