I've been using Doit.im for some time now, and so far I was quite satisfied. But there is one really important feature, that people are still missing: backup of OUR data.
There are currently 36 "export" and some more "backup" threads. The only thing we keep hearing over, and over again: "we are considering this feature now". You probably realized that you couldn't fob us off with that forever, so you started talking about this "open API", making it possible for other developers to build a backup feature. Fair enough - I would even spend some of my time to build a simple web app for everyone to backup their data. But after asking for an API key, I got the following answer:

"Our open API supports creating data, does not support exporting data."

Seriously?! This made me come to the following conclusion. You either:
1.) Ignore your customers. Since I've seen you implement some suggestions within days, I don't think that's the case.
or
2.) You consciously keep people from exporting their tasks, so they have to stick to your service.

The second one is a big accusation, but it makes sense. This is a basic feature, that EVERY professional service offers. It has been requested for years and has a huge demand (as I said, it's around 40-50 threads with even more people supporting this idea). First you "don't plan it", then you "will consider it strongly" and finally you come up with an open API, which supports... no reading operations? For me as a software developer, that's rubbish. Do you really think you can keep people from changing their todo management service by not offering any export functionality? Quite the contrary - you lose so many customers that either leave or don't join in the first place BECAUSE of a missing backup feature.

Finally, you always ask, why we want that feature so much. So let me put it that way: people don't trust you. People don't trust ANY web service completely, especially if it involves our private data. You can assure us how our data is perfectly safe as much as you want. It's still OUR data, and we have any right to have local backups.

If you want to maintain any creditability, please don't come up with any other automatic answer like "we're considering it strongly" or "your data is perfectly secure". We've heard it all, and we want to see that you start listening to your paying customers.