They appear to log both when you hover over the input box without clicking, and when you click it and enter text in addition to the aforementioned time delay trigger (that I didn't test).
BLANKED is inserted where some of the data could potentially be personally identifiable information. Of note is the "clearcounter". They apparently evaluate how many times you clear the data. The ajax call is apparently a more general function as they must supply the trigger.
Here is some of the data they are transmitting:
[{"user": "BLANKED","page_id":"BLANKED","posts":[["censorlogger",{"cl_impid":"BLANKED","clearcounter":0,"instrument":"composer","elementid":"BLANKED","parent_fbid":BLANKED,"version":"x"}, BLANKED,BLANKED]],"trigger":"censorlogger"}]
BLANKED is inserted where some of the data could potentially be personally identifiable information. Of note is the "clearcounter". They apparently evaluate how many times you clear the data. The ajax call is apparently a more general function as they must supply the trigger.