This wasn't really feasible before, but once Segwit activated a ray of hope came forth.  With Segwit implemented and gradually growing, and with Lightning now being examined more thoroughly, micro transactions are more of a possibility in bitcoin.

See project in my signature for details, the first phase of the project was proof of concept in the BCN GUI. The next phase will be doing the same thing in GUI settings in a bitcoin wallet (providing the option for microdonations at certain thresholds, for example), but in that latter context, the precondition has always been (1) Segwit and (2) a working Lightning implementation.

Cheers

(Note:  The 'first implementation' on the abis.io page is a dead link due to reorg of the BCN website, please scroll down to where it has a link described as 'bytecoin (BCN) ~ discussion' for more coverage of how this was implemented there for the proof of concept; it is certainly hoped that this will not only be able to be done in BCN (where it was first implemented) and also soon in a bitcoin wallet, but later in various other crypto systems as well.)

And for some other details of a project which will enable microtransactions which was spawned by ideas which were first discussed in the ABIS repo at https://github.com/ABISprotocol/ABIS -- please see http://subsatoshi.org/ which was developed by a colleague of mine, ktorn, and some other folks.