I agree with webfreak08 you should focus on the important point of contacts not being worried your customer can't contact you by their preference.

Consistancy is the key. Yes Having MSN, AIM, Yahoo, ICQ, Skype, Phone, Trouble Ticket, Live Support, Forum may work very well in a very small business because there is little demand. But if your thinking long-term I highly doubt you will still be doing that if you had 10,000 Customers. If you are consistant and reliable in the main areas of: Phone, Ticket, Live Support and Forum you don't need anything else because using 10, 20 methiods Point of Contact may work against you in a long run if for example your company was hit by a DDoS attack and all 10,000 Customers were screaming at you in all the contacts mentioned above.