Sweden's credentials as a "neutral" state were pretty impecable going back some 150 years nearly. They were staunch supporters of the League of Nations and had intimated that they would stay out of any conflict. They were also experienced in keeping an eye on and co-existing with the two main powers in the area, Germany and Russia. The premise that guaranteed Sweden's survival was that if ever Russia and Germany were to fight neither could spare troops to sort out Sweden if the Swedes made sure they were armed. From 1938 until 1943 Sweden's defence budget and military spending increased dramatically, the signal was sent that the Swede's would not be a push-over and by 1939 the main protagonists attention was elsewhere.

In order to sweeten the deal the Swede's were very receptive to pressure from Nazi Germany and yielded many concessions, right of transit across Swedish territory and use of the Swedish Rail Network to transport German troops and equipment during the occupation of Norway was one such concession - I do not believe that the Norwegians will ever totally forgive Sweden for that.

Geographically Sweden was not as important as Denmark or Norway to Germany. Like Norway, Sweden's armed forces were all conscripts and 1 million of them formed a "Homeguard" force. Norway's armed forces and homeguard scared the Germans rigid in late spring and early summer of 1940, they had the advantage of knowing the terrain and they could shoot, since the mid 1800's every boy over the age of 14 in Norway was taught to shoot a rifle. Rifle clubs in Norway still to this day receive massive financial support from the Norwegian Government. The Germans used about 550,000 troops to garrison Norway, which had a population at the time of less than 4 million, which works out at one German soldier for every seven Norwegian civilians - the prospect of facing the same problem in Sweden would not have appealed to the Germans - they simply did not have the manpower.

Yes Sweden made money from the war, exactly as the USA did in the First World War and for the first part of the Second World War. Sweden also freely gave aid to her neighbours for post-war construction and received all but 800 of Denmark's Jews as bona fide asylum seekers in order to save them from the Nazis. The attitude towards Norwegian resistance fighters up until 1943 was to hand them over to the Germans, after it became obvious that Germany was not going to win the war in 1943 that policy changed, but once again it is a thing that the Norwegians remember.

The ball-bearing flights between Stockholm and Leuchars by the fledgeling BOAC during the war saw an unarmed Mosquito climb to maximum height over Sweden to make the straight shallow diving run for Britain. The aircraft was "clocked" by the Germans at a speed in excess of 600 knots, I do not believe that any were lost to enemy action in the 520 flights that were made.