IT Companies
Most IT companies offer a large range of different services, and often specialise in a specific service, as this can be very lucrative. Lots of companies offer basic services such as e-commerce, telecommunications and web development, but also more specialised areas like semiconductors. Due to the many different components involved in IT, it can mean that there may be an IT company specialising in every aspect, even some of the more obscure types.
Taking this into account, it can mean that if you do wish to consult an IT company for whatever reason, chances are there will be a type out there even able to specialise in what you need. If you are interested in or need help with a more general area in IT, then there will be a great deal of choice of IT companies, so you can take the time to get the best possible deal.
A large percentage of IT companies offer consultancy as opposed to equipment or other physical IT related items, and consulting such a company would be a great opportunity to get the best information about your topic or problem. It may pay to consult more than one company, especially if the issue at hand is particularly complex or if there is any conflicting information and advice. Either that, or try a company that specialises in a particular aspect of consultancy, so that the level of advice given to you will be higher than if you went to a company that might be more generalised.