10.

Expenses by nature

Breakdown of expenses by nature for the years ended 31 December 2018, 2017 and 2016 is as follows:

Cost of revenue:


	2018			2017			2016
Depreciation and amortization		(4,287,974	)		(2,596,980	)		(2,203,351	)
Treasury share		(1,884,556	)		(1,669,807	)		(1,491,503	)
Interconnection and termination expenses		(1,763,414	)		(1,607,079	)		(1,420,233	)
Employee benefit expenses		(1,202,485	)		(1,046,544	)		(859,143	)
Cost of goods sold		(1,108,734	)		(870,226	)		(551,656	)
Frequency expenses		(622,390	)		(278,727	)		(229,396	)
Radio expenses		(508,884	)		(844,941	)		(828,222	)
Cost of revenue from financial services (*)		(348,492	)		(270,366	)		(68,546	)
Transmission expenses		(326,080	)		(218,221	)		(139,185	)
Universal service fund		(256,454	)		(221,431	)		(192,045	)
Roaming expenses		(226,806	)		(177,258	)		(128,429	)
Billing and archiving expenses		(50,929	)		(55,185	)		(61,647	)
Others		(1,558,795	)		(1,493,409	)		(1,063,251	)

		(14,145,993	)		(11,350,174	)		(9,236,607	)

(*)	As at 31 December 2018, depreciation and amortization expenses includes depreciation and amortization expenses related to the financial services amounting to TL 12,053 (31 December 2017: TL 6,343; 31 December 2016: TL 1,677).

Selling and marketing expenses:


	2018			2017			2016
Selling expenses		(555,158	)		(898,936	)		(757,869	)
Marketing expenses		(551,127	)		(532,989	)		(518,382	)
Employee benefit expenses		(440,976	)		(394,421	)		(354,380	)
Frequency usage fees related to prepaid subscribers (**)		—			(82,994	)		(186,530	)
Others		(79,453	)		(96,080	)		(93,786	)

		(1,626,714	)		(2,005,420	)		(1,910,947	)

(**)	As of 31 December 2018, Frequency usage fees related to prepaid subscribers are shown under net impairment losses on financial and contract assets according to IFRS 9.

Administrative expenses:


	2018			2017			2016
Employee benefit expenses		(425,681	)		(346,151	)		(277,438	)
Travel and entertainment expenses		(38,406	)		(30,957	)		(18,913	)
Consultancy expenses		(38,252	)		(50,247	)		(54,315	)
Collection expenses		(37,525	)		(20,415	)		(20,827	)
Maintenance and repair expenses		(26,867	)		(24,342	)		(20,315	)
Rent expenses		—			(36,280	)		(30,314	)
Net impairment expense recognized on receivables		—			(36,278	)		(211,384	)
Other		(106,639	)		(100,526	)		(88,343	)

		(673,370	)		(645,196	)		(721,849	)

Net impairment losses on financial and contract assets:


	2018			2017
Net impairment losses on financial and contract assets		(346,390	)		—

		(346,390	)		—