What a great question / thanks for asking. Here's how some of the top experts are getting more calls.

1. Link Clarity on Social Profiles ( http://clarity.fm/me <- click to get your link)
- Obvious: Twitter, LinkedIn, Google+, Facebook
- Others: Email Signature, Blog Widget https://clarity.fm/account/widget

Pro Tip: Schedule Tweets, Facebook Post or LinkedIn Message every week promoting your URL (I use www.bufferapp.com to do this)

2. Engage On Clarity
- Use your VIP link to offer free calls to build your reputation & ratings (+ Reviews) https://clarity.fm/account/vip-link
- Answer questions on Clarity (5% of question end up in a call request) https://clarity.fm/questions/f/status=open
- Promote your Clarity profile link (Views = Quality) / View above
- Ensure (if you have the skills) you set your Areas of Expertise and use Keywords that people search for .. essentially anything that helps them make money (Fundraising, Marketing, Sales, Biz Dev, Legal, etc)

3. Engage Outside of Clarity
- Quora: Many of our experts have migrated their questions from Quora to Clarity Answers (Copy/Paste & Answer). It's a hack, but legal and fair. These answers show up on their profile so it help build credibility.
- Quora #2: Answer questions on Quora, and at the end of your answer, link your Clarity profile URL
- LinkedIn: Engage in Q&A within groups and add your Clarity profile URL at the end of your post.
- Guest Post (Other People Blogs) and at the end of the post, write "If you'd like to discuss further, call me on Clarity"
- About.me - Add your Clarity URL
- Forums: Depending on your expertise, you can find Forums to help others (answer questions) but always end with your Clarity profile URL

I'm assuming you seeing a trend...

The more calls you do on Clarity + Ratings you get + Answers that get voted high quality (for a Topic) the higher you'll rank within our search.

That being said, 70% of my calls come from me promoting my Clarity link and I'm personally making $3-4K per month right now (and that doesn't include any #3 tactics (Yet! :).