Today I noticed that a company in my industry has put up sites like www.brandnamewidgets.com, which are disclosed on-site as being "powered by" the original domain. Even though the sites are devoted to the brand name widgets in question, all the links go to the company's domain where those items (and other brands) are actually sold. Is this considered a good SEO strategy? If it's legitimate and works to get good rankings and customers, would you recommend doing something similar?

Interlinking your own sites in general is not a good idea. You will end up with an unnatural circular structure, that may count against you.

I agree. This company appears to have put up these quasi-doorway sites as a larger link-building strategy, however, so they represent a small percentage of their links and probably will never be detected. I guess my bigger question is how can we possibly compete when there are so many sites that use these shifty tactics, and the shiftiness works and isn't penalized? It's kind of depressing.

forget about them and just concentrate on what you are doing... solid content and good site usability will win out... build links... post on blogs and article sites to promote your brand and site... it works but is not easy... those who try quick methods are always looking for trouble

I never spend too much time thinking about what my competition is doing. If you do that, you'll spend all your time trying to figure it out and not actually doing.

at this stage the web is a battle with yourself... you need to Just Do It and wait for the income to come to you... just don't stop moving forward and income will catch up

It's called building a network (of brands or products) and it's a great way to build authority, community, and sales/traffic.