Pass IDs as array, not comma separated string

Fix the issue with blank listings on map if there are multiple listings in the same location:

![screen shot 2014-11-28 at 15 50 32](https://cloud.githubusercontent.com/assets/429876/5228680/5ee81440-7716-11e4-9f04-7ed6a30ee78d.png)

Pass the ids as an array, not as comma separated list.
should this logic be moved to marketplaceservice?