Santos's family comes from Brazil and Macau. His family is very wealthy, with most of their wealth coming from a chain of casinos they own in Brazil and Macau. It is not entirely clear, but it is believed the family also gets income from the financial sector. Relatives of Santos currently live in Brunant, Brazil, Macau, Hong Kong, the United States, Switzerland, Liechtenstein and Juliana.
In the summer of 2005, Santos tried to buy FC Drenthe (who were having a strong period, as runners-up of the 2003-04 First League, and winners of 2002-03 and 2001-02), but the deal fell through. Santos then bought Grijzestad University S.C., and got involved with the sports administration at Grijzestad University. Santos managed to bring in former Brazil international Mazinho to be the coach/manager of the team, and Santos and Mazinho brought in numerous Brazilian players to the team.
Though Grijzestad University S.C. performed well in the 2005-06 Second League, with Brazilian Zudinho scoring a record 20 goals, the team only achieved third place and was not promoted to the First League. Frustrated, Santos fired Mazinho and brought in another former Brazilian international, Müller, to be the manager. However, in the 2006-07 Second League, the team couldn't manage better results, and finished 3rd again.
By the summer of 2007, Santos had rumouredly managed to get Grijzestad University S.C. into financial trouble, and the team let go Müller (replacing him with Brunanter coach Martin Planas) and sold Veve (for €5'000'000, the record transfer fee for a Second League team at the time and only a hair under the overall Brunanter record at the time). Around this time, Santos also convinced Grijzestad University administrators to start a special sports scholarship for Lusophone students, with the intention of gathering youth players for GUSC, which brought around two dozen students from Brazil, Portugal, Cape Verde and Macau to the University (of these, a few would go on to play for Grijzestad University S.C., including Razindo and Lihueno).
However, the team finished 4th in the 2007-08 Second League, and St. Marks Koningstad bought Zudinho. In the 2008-09 Second League, GUSC finished an unimpressive 6th. At this point, Santos became very frustrated and sold the team. The Lusophone scholarship program at the Grijzestad University was stopped soon after his departure, although the recipients already at the University were allowed to remain studying there.
In 2010, Dominic Santos moved to Liechtenstein. However, he continues to visit Brunant regularly, and is a major shareholder (believed to be 10%-20%, but the records are not publicly available) of the Villa Fulvia Hotel and Casino. It is also believed that Santos bought a residence in Juliana in 2014, as he has been seen there several times.