said 1 year, 4 months ago:
I think it depends on the needs of each company and what is your target audience. A good social media campaign can be more successful if you use the right tools, and usually the more media used to advertise your product or service is likely to reach more people. Of course nothing is achieved by having many channels, if there is no time to handle them.
Rather than thinking of a number of channels to use, I would say that it is appropriate to cover the areas that make a successful campaign.
Use tools that help you network, promote and share. Pick as many tools you can handle that are appropriate to reach your target and is likely to get what you are looking for.