How can I determine link popularity?
I want to sort links based on the link's popularity. However, I cannot do what search engines are doing (indexing the entire internet to check for backlinks). So, my current solution is checking to see how many Facebook Likes do the links have. I want to also see how many Tweets or +1s do the links have, but Twitter/Google do not provide an API for this.

What are some other ways to determine link popularity?
How can I determine link popularity?
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I want to sort links based on the link's popularity. However, I cannot do what search engines are doing (indexing the entire internet to check for backlinks). So, my current solution is checking to see how many Facebook Likes do the links have. I want to also see how many Tweets or +1s do the links have, but Twitter/Google do not provide an API for this.

What are some other ways to determine link popularity?