Prepayments and other current assets consist of the following:


			As of December 31,
			2020		2021
			RMB		RMB		US$
Receivables on behalf of third party advertising companies	(i	)		—		12,599		1,977
Prepaid service fee				12,028		11,410		1,790
VAT and other surcharges				10,467		5,618		882
Investment in a convertible loan				—		4,221		662
Loans granted to equity investees	(ii	)		500		3,000		471
Office rental deposit				636		919		144
Prepaid media cost				—		551		87
Receivables from sales of shares on behalf of employees				11,060		180		28
Refund from prepaid media cost				6,838		—		—
Others				7,484		8,172		1,282

Total prepayments and other current assets				49,013		46,670		7,323

(i)	Starting from January 1, 2021, the Company has fully exited the Targeted Marketing business and this balance represents the receivables the Company acts as agent and collects on behalf of third party advertising companies for targeted marketing related services.

(ii)

For the years ended December 31, 2019, 2020 and 2021, the Company recognized impairment charges on loans granted to equity investees of nil,

RMB4,500 and RMB528 (US$83)

The Company evaluates the impairment of the equity investments without readily determinable fair value along with loans the Company granted to those investees.