Why is an off-plan property a successful investment in Dubai?

Off-plan properties in Dubai are considered successful investments for several reasons: 

Price appreciation: Off-plan properties in Dubai are often sold at a lower price compared to completed properties, which can result in significant price appreciation once the property is completed and ready for occupation. 
High rental yields: Dubai has a large demand for rental properties, which can result in high rental yields for property investors. 

Tax benefits: Dubai has a very attractive real estate investment climate with no property tax, no capital gains tax and no income tax.
Strong developer reputation: Dubai has a reputation for having reputable and well-established property developers, which can provide a sense of security for investors.

Government support: The government of Dubai has been very supportive of the real estate industry, and has implemented policies to encourage foreign investment in the property market. 

Strategic location: Dubai is a strategic location for business, tourism, and trade, which can attract more investors to the area. It's important to note that while off-plan properties can be a successful investment, it's important to research the developer, location, and the property itself and consult with a legal professional and a financial advisor to ensure that all legal requirements are met and that you understand the tax and regulatory implications of owning a property in Dubai, and also to consider the risk factors such as the property market, the developer's reputation, the payment plan, the property area and the time of the completion.