Why don't you create a dedicated remote control app for iOS and Android?
Your sling boxes include the necessary hardware, I.e Ethernet/wifi and an infrared blaster in order to turn our handheld devices into universal remote controls.
It would give buyers 2 reasons to buy a sling box. For many people the frequency in which a sling box is currently required is minimal, making it hard to justify a purchase. However add the ability to use their phones as a single universal remote and the frequency of use increases 10 fold and therefore the justification to buy a slingbox becomes easier.
Plus you could charge separately for the remote app, maybe even in app purchases per device you want to control.
Whilst I'm at it. I have an iMac. I can stream my Cablebox to this iMac from downstairs through my slingbox. That's great. But without a dedicated desktop app I cannot use the remote that came with my mac to change channels through my slingbox. With a dedicated app and ability to use an apple remote I can use an iMac or any desktop computer as a Remote controlled TV in a room that doesn't have one. In fact I could start getting rid of dedicated TV's all over the house. Buying a slingbox would theoretically be a cost saving since I'd only have to purchase a single screened device for each room, as oppose to 2