| Summary of Significant Classes of Amortizable Intangible Assets | The following tables provide a summary of our significant classes of amortizable intangible assets:
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
|   |    |  |   |  
|   |    |   |   |    | Accumulated |   |    |   |   |  
|   |    | Cost |   |    | Amortization |   |    | Net |   |  
|   |    |   |   |    |   |   |    |   |   |  
|   |    |  |   |  
| Customer lists and contracts |    |  |  |   |    |  |  |  |    |  |  |   |  
| Domain and brand names |    |  |  |  |    |  |  |  |    |  |  |  |  
| Favorable and assigned leases |    |  |  |  |    |  |  |  |    |   | —    |   |  
| Subscriber base and lists |    |  |  |  |    |  |  |  |    |  |  |  |  
| Author relationships |    |  |  |  |    |  |  |  |    |  |  |  |  
|  |    |  |  |  |    |  |  |  |    |  |  |  |  
| Other amortizable intangible assets |    |  |  |  |    |  |  |  |    |  |  |  |  
|  |  |   |   |  |  |   |   |  |  |   |   |  |  
|   |    |  |  |   |    |  |  |  |    |  |  |   |  
|  |  |   |   |  |  |   |   |  |  |   |   |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
|   |    |  |   |  
|   |    |   |   |    | Accumulated |   |    |   |   |  
|   |    | Cost |   |    | Amortization |   |    | Net |   |  
|   |    |   |   |    |   |   |    |   |   |  
|   |    |  |   |  
| Customer lists and contracts |    | $ | 24,186 |   |    | $ | (23,006 | )  |    | $ | 1,180 |   |  
| Domain and brand names |    |   | 19,978 |   |    |   | (19,704 | )  |    |   | 274 |   |  
| Favorable and assigned leases |    |   | 2,188 |   |    |   | (1,975 | )  |    |   | 213 |   |  
| Subscriber base and lists |    |   | 8,647 |   |    |   | (8,531 | )  |    |   | 116 |   |  
| Author relationships |    |   | 3,070 |   |    |   | (2,771 | )  |    |   | 299 |   |  
|  |    |   | 2,052 |   |    |   | (2,044 | )  |    |   | 8 |   |  
| Other amortizable intangible assets |    |   | 1,411 |   |    |   | (1,352 | )  |    |   | 59 |   |  
|  |  |   |   |  |  |   |   |  |  |   |   |  |  
|   |    | $ | 61,532 |   |    | $ | (59,383 | )  |    | $ | 2,149 |   |  
|  |  |   |   |  |  |   |   |  |  |   |   |  |  |