Here are the top 30 Social Bookmarking Sites rated by a combination of Inbound Links, Google Page Rank, Alexa Rank, and U.S. traffic data.

 Although no traffic metrics are completely accurate… I do believe the data below to be useful for gauging relative audience size.

 

1. digg.com

117,796,083  Inbound Links
16,964,445  Compete Monthly Visitors
8,700,000  Quantcast Monthly Visitors
98  Alexa Ranking
Page Rank: 8
 

2. Technorati.com

75,306,437  Inbound Links
3,231,709  Compete Monthly Visitors
1,400,000  Quantcast Monthly Visitors
216  Alexa Ranking
Page Rank: 8

 

3. del.icio.us

171,593,051  Inbound Links
1,699,128  Compete Monthly Visitors
1,300,000  Quantcast Monthly Visitors
248  Alexa Ranking
Page Rank: 8

 

4. Propeller.com

997,000  Inbound Links
1,454,912  Compete Monthly Visitors
2,180,176  Quantcast Monthly Visitors
2,308  Alexa Ranking
Page Rank: 7

 

5. StumbleUpon.com

19,050,177  Inbound Links
1,313,586  Compete Monthly Visitors
695,239  Quantcast Monthly Visitors
300  Alexa Ranking
Page Rank: 8

 

6. reddit.com

45,307,577  Inbound Links
1,226,467  Compete Monthly Visitors
344,383  Quantcast Monthly Visitors
852  Alexa Ranking
Page Rank: 7

 

7. Fark.com

11,438,723  Inbound Links
306,597  Compete Monthly Visitors
1,767,165  Quantcast Monthly Visitors
1,958  Alexa Ranking
Page Rank: 7

8. MyBlogLog.com

1,742,265  Inbound Links
1,972,847  Compete Monthly Visitors
84,922  Quantcast Monthly Visitors
432  Alexa Ranking
Page Rank: 7
 

9. Slashdot.org

13,555,035  Inbound Links
724,424  Compete Monthly Visitors
269,884  Quantcast Monthly Visitors
579  Alexa Ranking
Page Rank: 9
 

10. kaboodle.com

100,266  Inbound Links
1,751,763  Compete Monthly Visitors
851,858  Quantcast Monthly Visitors
9,125  Alexa Ranking
Page Rank: 6
 

 

11. Bloglines.com

50,717,948  Inbound Links
382,663  Compete Monthly Visitors
103,711  Quantcast Monthly Visitors
853  Alexa Ranking
Page Rank: 9
 

 

12. newsvine.com

24,200,775  Inbound Links
315,857  Compete Monthly Visitors
203,761  Quantcast Monthly Visitors
3,977  Alexa Ranking
Page Rank: 7
 

13. blinklist.com

23,770,576  Inbound Links
243,277  Compete Monthly Visitors
165,306  Quantcast Monthly Visitors
4,647  Alexa Ranking
Page Rank: 6
 

 

14. netvouz.com

8,112,272  Inbound Links
75,507  Compete Monthly Visitors
54,325  Quantcast Monthly Visitors
15,048  Alexa Ranking
Page Rank: 6
 

15. clipmarks.com

164,419  Inbound Links
196,107  Compete Monthly Visitors
147,131  Quantcast Monthly Visitors
6,740  Alexa Ranking
Page Rank: 6
 

 

16. Furl.net

49,595,144  Inbound Links
148,975  Compete Monthly Visitors
57,547  Quantcast Monthly Visitors
4,112  Alexa Ranking
Page Rank: 8
 

17. MisterWong

13,214,146  Inbound Links
25,416  Compete Monthly Visitors
3,432  Quantcast Monthly Visitors
1,889  Alexa Ranking
Page Rank: 7
 

 

18. dzone.com

1,065,009  Inbound Links
100,784  Compete Monthly Visitors
117,897  Quantcast Monthly Visitors
5,187  Alexa Ranking
Page Rank: 6
 

19. ma.gnolia.com

13,701,444  Inbound Links
110,662  Compete Monthly Visitors
32,363  Quantcast Monthly Visitors
7,454  Alexa Ranking
Page Rank: 7
 

20. Tailrank.com

5,320,211  Inbound Links
71,563  Compete Monthly Visitors
35,783  Quantcast Monthly Visitors
28,920  Alexa Ranking
Page Rank: 7
 

 

21. ShoutWire.com

168,480  Inbound Links
101,738  Compete Monthly Visitors
55,337  Quantcast Monthly Visitors
10,552  Alexa Ranking
Page Rank: 6
 

22. simpy.com

13,107,730  Inbound Links
62,645  Compete Monthly Visitors
49,205  Quantcast Monthly Visitors
10,948  Alexa Ranking
Page Rank: 7
 

 

23. BlogMarks.net

9,748,453  Inbound Links
61,740  Compete Monthly Visitors
28,075  Quantcast Monthly Visitors
11,880  Alexa Ranking
Page Rank: 6
 

24. BlueDot.us

1,159,780  Inbound Links
107,717  Compete Monthly Visitors
60,045  Quantcast Monthly Visitors
12,072  Alexa Ranking
Page Rank: 6
 

25. Spurl.net

18,628,253  Inbound Links
42,300  Compete Monthly Visitors
3,483  Quantcast Monthly Visitors
14,300  Alexa Ranking
Page Rank: 6
 

 

26. Spotplex.com

541,599  Inbound Links
52,176  Compete Monthly Visitors
15,106  Quantcast Monthly Visitors
42,809  Alexa Ranking
Page Rank: 6
 

27. linkswarm.com

150,842  Inbound Links
14,504  Compete Monthly Visitors
10,476  Quantcast Monthly Visitors
47,267  Alexa Ranking
Page Rank: 5
 

 

28. Spotback.com

97,564  Inbound Links
42,838  Compete Monthly Visitors
5,037  Quantcast Monthly Visitors
42,015  Alexa Ranking
Page Rank: 5
 

 

29. PlugIm.com

161,039  Inbound Links
48,078  Compete Monthly Visitors
2,000  Quantcast Monthly Visitors
13,133  Alexa Ranking
Page Rank: 5
 

 

30. MyBookmarks.com

25,191  Inbound Links
10,934  Compete Monthly Visitors
7,727  Quantcast Monthly Visitors
108,226  Alexa Ranking
Page Rank: 5