It can be tempting to think of Viking society as a sort of pioneer society where everyone did everything, but in reality, it was a highly organized society where individuals could follow a number of different paths from warrior and trader to craftsmen or even a skald. In the past, it was assumed that Viking society was static and kinship via the male line was the overwhelming factor in deciding who succeeded or who did not. Or another way of looking at it is that a man's birth determined his profession and status. However, recent studies point to a far more fluid system.
While wealth was primarily land based, it was also possible for a freeman to acquire wealth through joining a felag and trading mission. A felag is literally a fellowship and represented a group of warriors who were bound to serve one leader in times of war. Often because the voyages combined both an element of raiding and trading, there would also be a civilian partnership where the member of the felag was also a part owner of the ship and thus entitled to part of the proceeds.
As the Viking era progressed, the distinction between trader and warrior appears to have widened and you have some warriors hiring out their sword arms. Most famous was the Varangian Guard who served the emperor in Byzantium. The word Varangian comes from the old Norse "var" who means vow and "gengi" which means companion or sword fellow. So these men were the men of the vow and were considered to be amongst the best warriors in the Viking world. Var was also a Norse goddess who was involved in the keeping of oaths.
Dating from the mid ninth century, the Varangian Guard was perhaps over glamorized by the Icelandic saga writers as the men serving in the Guard often return home dressed in exotic clothes, laden with wealth and honour. It is one way for landless warriors to acquire status. It also served to help provide an outlet for such men and to create a far more stable population in Scandinavia after the main trading routes were established.
It was basically the Viking foreign legion who were charged with being the personal body guard of the Byzantine emperor. Future kings such as Haraldur Sigurthsson learned their trade there. In the case of Harldur, he served for ten years, incognito in about 1040. According to Snorri Sturulson, Harldur served all over the Mediterranean, even perhaps visiting Jerusalem as the captain of the military escort for pilgrims to the Holy Sepulchre. But basically, he amassed a huge treasure horde which he used to finance his bid for kingship. When he fell foul of the Empress Zoe, he escaped, and used his men to rock the boat over a massive iron chain that blocked the harbour. Eventually he did become king of Norway.
A variety of rune stones in Scandinavia proclaim wealth derived from service in the Varangian Guard.
Towards, the end of the Viking age, the Varangian Guard appears to have been mainly made of displaced Anglo Saxons.
It is through the exploits of the men of Varangian Guard and others that one can see that Viking society was in fact fluid and much depended on the skill with which the warrior used his sword arm.