What are some alternatives?
When comparing Lasso Content Curation and Diigo, you can also consider the following products
Pocket Explore - A human curated version of the web
Pocket - When you find something you want to view later, put it in Pocket.
wallabag - Save the web, freely.
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
PostDiva - Really clever content curation for social media managers
Pinboard - Pinboard is a personal archive for things you find online and don't want to forget.