Which one do you prefer? Streaming or downloading 3D files ?

Streaming isn't compatible with every single 3d printer out there and has limitations still. Some buyers want to be able to re-scale a design and some streaming processes out there don't always allow that. Also internet speeds can be an issue. On the buyers end there is always the worry that if the print fails either by stream process or some other factor, would they have to re-pay to re-print? By allowing downloads, a seller can reach a greater audience because the buyer isn't warded by streaming limitations and concerns. Also buyers are more likely to pay for a downloadable as they can modify the design to fit their printer, and their needs.

As streaming processes and compatibility improve, I believe more designers will make the change. I myself am slowly making the switch to streaming. On sites such as Cgtrader, I am making streaming cheaper than purchasing the downloadable.

Thanks for your reply!!
I saw that many people selling 3D print models as well besides allowing buyer to stream and download. Personally, I feel that the price of most 3D print models are quite high. I wonder if people will be willing to pay such a high price for them. Do you think selling 3D print model is much better than allowing buyer to stream/ download or on the other way round?

A lot of people out there don't have access to a 3d printer so they are willing to get something printed through a 3rd party like Shapeways and CG Trader if they find a unique design they can't find anywhere else. Price still is a problem through using 3rd parties to print a design as designers don't make much profit. Cg trader has some of the highest prices I've seen for their "Get Printed" now feature. My Chibi Alice costs $56 to get printed through CGtrader where as on Shapeways it costs $19. I make more of a profit on shapeways than here on CGtrader when It comes to having a 3rd party company print a design but I make far more profit when it comes to selling stream/downloadable files for printers.

As 3d printers become more cost friendly for the average consumer, the demand for quality streamable/downloadable printable files will go up. Stream vs download I see as as a own vs not to own. If a buyer as no intention to print multiples of a files, streaming may be the way to go. If a designer allows downloads of a design, the buyer can modify and print as many copies as they wish. And like anything digitally downloadable on the internet, doesn't guarantee it will be protected from illegal uses.