The Bulgarian fast-track Citizenship by Investment program was until recently utilized mainly by citizens of countries with poor visa-free travel conveniences, such as Russia, China, India, many countries from the Middle East, South Africa and others alike.
Surprisingly for many though, the flow from applicants from the United States skyrocketed in 2016 and 2017. Although the US passport is one of the best passports in terms of visa-free travel worldwide, the benefits of having EU (Bulgarian) passport for American citizens are manifold.
For instance, Americans who want to settle in Europe, be it Paris, Stockholm, Zurich, etc., they all need to fight the bureaucratic EU immigration procedures, which are comprehensive, time consuming and expensive, least to say. Otherwise they are allowed to stay visa-free in the EU countries for no longer than 3 months during any 6 months period. During this stay, unless the EU immigration formalities are fully arranged, the US citizen is neither allowed to work nor to perform other activities, which are preserved only for the citizens and legal residents of the European Union.
Other advantage for the Americans is the extremely low taxation in Bulgaria (that generally applies to Bulgarian passport holders). The Bulgarian legislation offers the lowest personal and corporate taxation in the whole EU and one of the lowest tax rates worldwide. Bulgarians pay only 10% tax on their profits (both personal and corporate). Inheritance tax, successions, etc. can be in many cases minimized and even legally avoided altogether. Additionally, holding Bulgarian (EU) passport, allows the individual to invest in real estate properties, which are otherwise not available for non-EU citizens.
You can read a very nice article with major input from our consultant Mr Dobrinov about the Bulgarian fast-track citizenship program in the eb5 investors. You can also download the article in PDF format.