Online marketing covers a wide variety of skillsets and technologies. Most firms in this space today were either originally a traditional marketing firm that
acquired a technology capability or were originally a technology firm that developed marketing expertise.
These firms can have significantly different solutions to the same problem. Ex-marketing firms strength is they tend to see the bigger picture and work toward integrated solutions which tie traditional efforts in with your on-line efforts. They tend to have a better understanding of branding and they also understand customer personalities better. Ex-technology firms tend to be apply to propose solutions which are solely on-line. Their strenghs are that they seem to have a better ability to apply technology to a specific solution.
Be sure to do your research when looking for a qualified online marketing firm.