depends....depends on how strong your application is, so you have all the documents they require? also depends on which country you are trying to get Visa from. Some are more strict on their requirements than others. Also, even after they approve for Visa, it is not available for pick up right away..you might need to wait 2 weeks til pick up.
Also depends on what type of Visa you are looking to apply.
Also, some countries require in person appearance..they do not accept agencies or 3rd parties.
What country are you referring to and what type of Visa? More information might help to answer your question.