We're running a campaign for specific industries within our target market.

Our main web site has a page for each industry.

We also own domains for each industry i.e: FoodWidgets.com, ElectricalWidgets.com, ChemicalWidgets.com.

Of the following methods, which is likely to make the best SEO improvements:

1. Just link each domain to the main web site
2. Forward each domain to the relevant page on the main site e.g. FoodWidgets.com (302) redirects to http://www.MainSite.com/industries/food
3. Create a single page "satellite" web site for each domain with the same content as the industry page on the main site.