If you are still doubtful about internet marketing then take a look at your competitor or rival companies, if you find them making progress overnight or getting customer in shortest possible time span then be rest assured that they are taking help of online marketing. Web marketing is not a big thing that you wont be understanding it or wont be able to comprehend the basic matrix of it. Even if you are having next to no knowledge you can still understand when a promising advertising agency would simplify everything.
You never have to be worried about budget or funds as online marketing is definitely much less expensive than traditional marketing. if you are wondering what E-marketing involves, well it requires affiliate marketing Web sites, SEO , e-commerce Web sites. It is logical that a normal business owner wont be able to understand everything so its better to work with a proficient agency.