Help solve the big SMS mystery!

The recently published 2010 Statistical Bulletin from MoIC contains some interesting statistics. One of the tables which I found mind-boggling shows the number of SMSes sent by B-Mobile, by destination and month.


While the total number of SMSes sent each month hovered between 4-7 million, the breakdown according to destination is quite puzzling. You would expect the number of local SMSes to be roughly the same throughout the year, or perhaps rising slowly as SMS technology is becoming more popular. But this is not the case: in January about 6 million local SMSes were sent. In May only 1.5 million (the minimum, shown below in red). Then in December almost 7 million (the maximum, shown below in blue).

The behaviour of the number of SMSes sent internationally is also surprising. Initially I though it would correlate with the tourist seasons, but it doesn't. The maximum was sent during the month of May, when more than 3 million international SMSes (!) were sent. Recall that May is the "low season" for local SMSes! The low season for internations SMSes is October, with only about 38 thousand (!).

There was no explanation for this behaviour in the bulletin, and I could not think of any. If you happen to have a rational explanation of these seasonal patterns, kindly share with us!

Month	Local	India	International	Total
January	5,871,653	29,537	319,347	6,220,537
February	5,425,189	29,161	51,740	5,506,090
March	4,338,791	30,607	768,966	5,138,364
April	2,955,411	26,873	1,727,654	4,709,938
May	1,539,770	19,377	3,216,825	4,775,972
June	2,811,034	2,169	2,221,017	5,034,220
July	4,772,030	1,927	638,255	5,412,212
August	5,471,331	25,298	199,703	5,696,332
September	4,381,286	16,632	121,698	4,519,616
October	4,769,441	19,674	37,876	4,826,991
November	3,989,168	16,202	13,143	4,018,513
December	6,916,785	20,374	13,505	6,950,664
Total	53,241,889	237,831	9,329,729	62,809,449