Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
|  |  | Year Ended December 31, | Year Ended December 31, | Year Ended December 31, |
| --- | --- | --- | --- | --- |
|  |  | 2019 | 2018 | 2017 |
| Passenger revenue: | Passenger travel | $38,831 | $37,457 | $36,152 |
| Passenger revenue: | Loyalty revenue - travel (1) | 3,179 | 3,219 | 2,979 |
| Passenger revenue: | Total passenger revenue | 42,010 | 40,676 | 39,131 |
| Passenger revenue: | Cargo | 863 | 1,013 | 890 |
| Other: | Loyalty revenue - marketing services | 2,361 | 2,352 | 2,124 |
| Other: | Other revenue | 534 | 500 | 477 |
| Other: | Total other revenue | 2,895 | 2,852 | 2,601 |
| Other: | Total operating revenues | $45,768 | $44,541 | $42,622 |
Question:
What is the loyalty revenue for marketing services as of 2018 for American Airlines?
Answer:
890