Tagging on Flickr has grown exponentially over time as more users have adopted the practice of adding tags to their photos on the site. Early tags tended to be simple labels like "birthday" or "vacation" but tags have become increasingly sophisticated as users describe concepts and annotate relationships between people, places, and events. The growing use and complexity of tags on Flickr now presents the greatest challenge of scaling the system to effectively support exploration of the vast tag space and increasing surface area for search and discovery.

1. Kakul Srivastava flickr.com/photos/kakul

2. tagging

3. tagging opportunities & challenges of scale

4. definitions

7. social

8. organic

9. scale

10. http://farm2.static.flickr.com/1113/534748833_f51c84dc71_b.jpg by: Rupert Taylor-Price • http://www.flickr.com/photos/rupertuk/534748833 equal to 100 heights of mt. everest

13. tags on flickr, trajectory break for a personal story

14. tags on flickr, trajectory

15. tags on flickr, trajectory

16. behaviors

17. growth is exponential

23. Monday 09:25

24. Monday 09:30

25. Monday 09:37

26. Monday 09:46

27. Monday 10:00

28. Monday 10:10

29. Monday 10:18

30. Monday 10:36

31. Monday 10:36 1 HOUR

32. Monday 10:36 1 HOUR 150 TAGS

33. Monday 10:36

34. Monday 10:45

35. Monday 10:56

36. Monday 11:16

37. Monday 11:47

38. Monday 12:00

39. Monday 12:20

40. Monday 12:20 3 HOURS

41. Monday 12:20 3 HOURS 767 TAGS

42. Monday 12:20

43. Monday 12:55

44. Monday 13:14

45. Monday 14:26

46. Monday 15:40

47. Wednesday 17:03

48. Thursday 10:49

49. Thursday 10:49 24 HOURS

50. Thursday 10:49 24 HOURS 11,000 TAGS

51. magic

52. sly, russian, mathematical magic

57. watch this space

60. more metadata: machinetags