This is the Data I Want -- Can I Go Home Now?
Imagine buying something in a store and having to remain there to use the thing. People want to find relevant data, evaluate whether they can obtain and use it, and then “take it home” to their chosen environment – Excel, MATLAB, R, Python…whatever.
They don’t want to have to learn your analytics tool / interface. Yes, you’ve put a lot of effort into a science gateway, and there are so many features and benefits for the user – the data is always up-to-date, you can pay attention to their usage decisions (and the latencies of resultant operations) in order to improve user experience over time, etc. This facility is akin to a separate room or lounge in a store where customers might be encouraged to get started with their new purchase – a playroom.
Your online analysis environment is a nice-to-have – it may certainly lower the barrier to “buying” the data because a user can kick the tires for a small part of their target application right then and there – but keep in mind that, ultimately, they’re going to want to take it home. Exporting data, in formats interoperable with your users' typical home environments, must be a first-class concern of a scientific data portal.