The principle is simple: buy produce directly from the small producers to avoid that a big part of their profit be taken by middlemen.
1) flying roses all the way from Ecuador to sell them in Europe at roughly the same price as those produced in Europe (because of the transportation cost) only worsen global warming. I guess it's ok for bananas and cocoa beans because they can't be grown in temperate climates. But flowers !?
2) I can't agree with a "faire trade" label that penalises local producers in Europe. Carrefour now sells fair trade flowers from South America when they could buy them from French (or other European) flower growers. That is outrageously not fair trade, because these big chains have actual power to seriously damage the European production by turning their back on their own country.