I was surprised by most people with the announcement that the "free" Twitter API was going away.
First there was a bit of a panic, I've been using the Twitter API for long time to build many applications, in the past for paid products, thankfully none at the moment, but I've had the idea for a couple that I was thinking about building at some point soon.
After thinking about the situation, I do actually think this could be a good thing in the long run, if done correctly. As is becoming the norm for Twitter operations, we get an announcement, with any details. I have a sense this is being used to gauge users reaction and get feedback before all the details are solidified.
Keep the API free for accessing your Twitter data. So anyone can still embed their own content on their own website, etc.
Keep the API free to empower "Login with Twitter".
Anything that reads content from other users, or users authenticated with oAuth, would be part of the paid tier.
Anything that writes content would be part of the paid tier.
That's it, pretty simple. The actual pricing should be tied to usage. With a generous base price, to encourage people to actually to use the API in a constructive way.
All scheduling tools would need to access the paid API tool. This seems reasonable, since they all charge users a monthly fee.
Most other tools that aggregate, summarize or analyze Twitter data from multiple users would likely be part of the paid tier.
Anyone wanting to show their own Tweets would be able to get a free API key to use. There may be some work need for tools to collect the users API keys, instead of using the current application keys.
Want to export/archive your own Tweets, you can still get an API key for that.
Since the announcement seems to imply there will be no free tier, we may not see anything like what I have described.
Getting rid of the free tier entirely would be a very bad mistake in my mind.
We just have to wait a few days and we'll see the plans.