If you can demonstrate that you have data that is of value, then link widgets definitely can help you in your marketing efforts. However, for the widget to start creating links for you without you having to touch each website owner individually, your content needs to be useful enough for people to track you down.
Take Majestic SEO's "Majestic Million" badge, for example. which we have been promoting for Majestic. The badge comes in two flavours - one lists how many sites link to yours, and the other says how where you rank in relation to the top 1 million websites in the world.
I just did a search on Google images and have found 302 sites using one version of the badge:
Now - it is important to understand that Google may or may not choose to accept these badges as a ranking factor. But the point here is that PEOPLE are accepting these as trust signals. A person would only put this badge on their site if: A; They were listed in Majestic's top 1 million websites in teh world and B: They were proud to be in that list and C: They felt their readers would be pleased to know they site was in that list.
It really doesn't matter what Google thinks, when you look at widgets this way, does it? Google just needs to keep up. In the meantime, Majestic are propogating their brand through to new audiences.
If you would like Receptional to devize a Link Strategy for you, you know what to do.