Given all the talk about "diversifying" the Algarve's markets and developing strategies to encourage winter touism, there is a very interesting recent article published (in Portuguese) on the Presstur website here:
http://www.presstur.com/site/news.asp?news=41279
Essentially, it confirms what I have been noticing the past few months in that several operators, including the largest by number of flights, ryanair.com have substantially reduced routes and frequencies serving Faro Airport in the winter period.
This is a major problem for the Algarve, particularly in the face of Lisbon and Central Portugal seeing increasing number of visitors year round.
I am not sure how this problem can be overcome, but one thing is for certain, the Algarve is facing an increasing number of challenges in even maintaining its profile as a destination for European Tourists.