Good competitor research can be a valuable tool when starting a SEO campaign. When initially looking to acquire links, backlink analysis of the top ranking competitors often provides an insight into the sort of links you will need to be getting to do well in that industry.
In competitive industries, backlink analysis can sometimes be an arduous task, taking a lot of time to trawl through links finding out which ones have potential and which ones have any value.
The downside to this method is that the majority of the links will be given to competitors for a reason, such as links from clients, and will often have a relationship behind them. These links, although valuable to the competition, are going to be difficult / impossible for you to get.
The trick is locating websites that link to multiple competitors as these will often be relevant to your niche but will also not show any particular bias towards a particular competitor meaning that the chance of getting the link are significantly increased.
To locate these relevant hubs perform a backlink check on the top 10 -20 urls that are returned for your target keyword. By exporting the results of these into a spreadsheet you can then sort the urls alphabetically to make it easier to spot any trends.
A lot of these links will tend to be from directories or other websites that are specific to your niche. Although directory links are often devalued, links from relevant, specialist directories can be quite valuable and can also help drive relevant traffic.