Year ended 31 December
Year ended 31 December
2019
2018
(RMB in millions)
(RMB in millions)
Revenues
377,289
312,694
Cost of revenues
(209,756)
(170,574)
Gross profit
167,533
142,120
Interest income
6,314
4,569
Other gains, net
19,689
16,714
Selling and marketing expenses
(21,396)
(24,233)
General and administrative expenses
(53,446)
(41,522)
Operating profit
118,694
97,648
Finance costs, net
(7,613)
(4,669)
Share of (loss)/profit of associates and joint ventures
(1,681)
1,487
Profit before income tax
109,400
94,466
Income tax expense
(13,512)
(14,482)
Profit for the year
95,888
79,984
Attributable to:
Equity holders of the Company
93,310
78,719
Non-controlling interests
2,578
1,265
95,888
79,984
Non-IFRS profit attributable to equity holders of the Company
94,351
77,469
other gains net .
we recorded net other gains totalling rmb19689 million for the year ended 31 december 2019 which primarily comprised of non-ifrs adjustment items such as fair value gains arising from increased valuations for certain investee companies in verticals such as fintech services social media and education as well as net deemed disposal gains arising from the capital activities of certain investee companies in verticals including transportation services and online games .
selling and marketing expenses .
selling and marketing expenses decreased by 12 % to rmb21396 million for the year ended 31 december 2019 on a year-on-year basis .
the decrease was mainly due to the reduction of advertising and promotion expenses as a result of improved operational efficiencies .
as a percentage of revenues selling and marketing expenses decreased to 6 % for the year ended 31 december 2019 from 8 % for the year ended 31 december 2018 .
general and administrative expenses .
general and administrative expenses increased by 29 % to rmb53446 million for the year ended 31 december 2019 on a year-on-year basis .
the increase was primarily driven by greater r & d expenses and staff costs .
as a percentage of revenues general and administrative expenses increased to 14 % for the year ended 31 december 2019 from 13 % for the year ended 31 december 2018 .
finance costs net .
net finance costs increased by 63 % to rmb7613 million for the year ended 31 december 2019 on a year-on-year basis .
the increase primarily reflected greater interest expenses resulting from higher amounts of indebtedness .
share of -loss / profit of associates and joint ventures .
we recorded share of losses of associates and joint ventures of rmb1681 million for the year ended 31 december 2019 compared to share of profit of rmb1487 million for the year ended 31 december 2018 .
the change was mainly due to non-cash charges booked by certain associates .
income tax expense .
income tax expense decreased by 7 % to rmb13512 million for the year ended 31 december 2019 on a year-on-year basis .
the decrease mainly reflected the entitlements of preferential tax treatments and benefits .
profit attributable to equity holders of the company .
profit attributable to equity holders of the company increased by 19 % to rmb93310 million for the year ended 31 december 2019 on a year-on-year basis .
non-ifrs profit attributable to equity holders of the company increased by 22 % to rmb94351 million for the year ended 31 december 2019 .

Question: What was the reason behind the increase in the 2019 general and administrative expenses?
Answer: The increase was primarily driven by greater R&D expenses and staff costs.