Despite all their "advanced technology" and "attempts" to stamp out spam in their serps, in the areas I have watched over the last few years the same spamming techniques show the top ten results for geo targetted "widget widget" searches as follows:
No 1 Doorway/Duplicate pages No 2 Doorway/Duplicate Pages No 3 Doorway/Duplicate Pages No 4 On topic result No 5 Doorway/Duplicate pages No 6 Doorway/Duplicate pages No 7 Local Business Directory - on topic No 8 Local University - on topic No 9 Doorway/Duplicate pages No 10 Local Directory - on topic
The only changes I have witnessed over the last 5 years are the same companies switching places in the top 20 results.
Techniques including multiple cross linking and invisible 1x1 pixel links predominate. IMO this is something they can never gain control over without human intervention.