I really miss the feature to scrobble to last.fm from the new web interface as we were able to do so in the last one.
Please, bring it back!
Updated on 2018-03-03
It is now possible to scrobble your listened tracks directly through last.fm. You just need to link you account in the Application Settings page.
In my case, it took some time for the link to start working, but it does scrobble across every device you use to listen to Spotify, including the webplayer.
Also, if you use the scrobbler in the Spotify Desktop app, you need to turn it off or you'll see double scrobbles.
Hope it helps. 🙂