LinkedIn is a social media site that'll be mos helpful to you, if you are working in a B2B business.
Apart from that, there is Twitter.
These two sites have members that are professional and creative.
It'll help you if you gain followers for your Professional service business by posting regular updates of your products.
The best social media platform for a professional service firm is LinkedIn. No about from that.
It provides a place for professionals to interact and network with each other. Apart from that, the only other social media platform I can think of is Twitter.
But very few professional niches can benefit from it, is what I think.