goes freemium with invite-only free plans has taken the decision to go freemium via an invite-only method.

Although has had only paid account tiers thus far, we initially conceived of as a freemium service. It took some time to get to this point, but we are now ready to make this vision a reality. […]

To get access to the free tier, you must have an invite. These invites are being distributed to current members on paid plans.

Unlike full paid-for accounts, free accounts have some limits such as maximum follower count, a more limited file storage and upload size. Whilst these are still limits, I don’t particularly see them as a restriction. Rather than keep certain features behind a paywall, ADN has decided instead limit how much each feature can be used. Free tier accounts are also totally reliant on paid-for accounts holder sending an invite, there’s no other way to get one (for now).

There are even incentives to use a 3rd-party app and start following more people which will up your storage space on ADN. This will encourage even more 3rd-party app use and may even address the concerns of ADN app developers that have made their apps free in response to Tapbots decision with Netbot (a decision, Tapbots say, was to spur adoption).

The timing for this is also no coincidence. Twitter’s version 1.1 of it’s API is about to come into force and today they launched an entirely new API just for ads.

It’s a smart move by and one that will definitely see a lot of users becoming increasingly frustrated with Twitter. It’ll be interesting to see in six months just how many free tier accounts are actively in use.