Link Builing is important for SEO and there is major impact of getting rank well. There is also less important of Reciprocal Links and also No-Follow Links still widely used (just recent news that Google now crawl the links even though it is no-follow or do-follow , they will judget on their own alogrithms not human control of linking method anymore). Link Baiting is one of popular techniques that make the large acquisition of links through word of mouth and quick spread throughout the blogs and niches website.
Today, I would recommend you to use Widget as Link Bait Strategy. Before you have widget , you have to thinking about these following.
- What is your target audience and what they are looking now?
- What function or information that can serve them and let them stay and get update of your information?
After that you will get the ideas what should be build for your targets. I would recommend you to start building widget from free website like http://www.widgetbox.com that you can also distribute through various channels.
There is some case study like Superpages widget that they got 22,000 links back from widget.