Linkbait is content (often a blog post) that's so important, useful, or controversial in a particular niche that it attracts a lot of buzz and loads of incoming links from other sources.
Linkbait posts are well thought out, and usually take a while to create.
It's worth investing some time and effort to create really high quality linkbait content, because it has the potential to bring you a ton of targeted traffic, links, and improved site rankings.
Once a week is ideal. The rest of the week you can make a shorter Utility Post each day.