In my own signature, I list certifications below my name. But that's because I consider postnominal letters only for educational or professional designations (PhD, JD, MD, MA, BSc, CPA, etc).
I've observed that people on LinkedIn sometimes chain their certs to their name ("Eric Geater, CISSP, CISR, CROSC, GPTQ", for example). I prefer to put those alongside my title, or below that. Also, because digital badges are available, they can offer third-party confirmation of your achievements.
There are others who may say that certifications are professional designations. I'll be interested to hear their input.
I've observed that people on LinkedIn may chain all their certs to their name ("Eric Geater, CISSP, CISR, CROSC, GPTQ", for example). I prefer to put those with my title or below. Now we have digital badges, too... and they're useful because a third-party is confirming your achievement.
That seems a reasonable approach. For the most part, I don't use my professional designations unless necessitated by context (e.g., speaking at a conference), but I may be a focus group of one in that regard. Ultimately, the issue is "am I answering a question?" or "am I adding a question?" by throwing some letters after my name. I find more designations fall into the latter than the former.
I am not sure the CC really ranks up there just yet. It's a good question. I know the (ISC)2 marketing department promotes the CC as leading to higher salaries, job offers, and respect. I haven't seen whatever data it based those claims on, but as a new credential, whatever data there is must be a moving target until it gets established. To me, it seems to be something akin to FINRA's Series 7. Even then, Series 7 has work-related, supervisory requirements - establishing a degree of work experience. In any case, I don't see people saying "Bernard Madoff, Series 7." It's more something designated on the job application or resume, but again time will tell.