like my idiomatic oop & c++ skills?

helloworld.cpp

#include <iostream>

class HelloSayer {
private:
	std::string greeting;
	std::string name;

	std::string makeMessage() {
		return this->greeting + ", " + this->name + "!";
	}

public:
	HelloSayer(std::string greeting, std::string name) {
		this->greeting = greeting;
		this->name = name;
	}

	void printHello() {
		std::cout << makeMessage() << std::endl;
	}
};

class HelloSayerFactory {
private:
	std::string greeting;

public:
	HelloSayerFactory(std::string greeting) {
		this->greeting = greeting;
	}
	
	HelloSayer *makeSayer(std::string name) {
		return new HelloSayer(this->greeting, name);
	}
};

int main(int argc, char *argv[]) {
	if (argc < 2) {
		std::cerr << "no name given" << std::endl;
		return 1;
	}

	HelloSayerFactory hsf("Hello");

	std::string username(argv[1]);
	HelloSayer *user = hsf.makeSayer(username);

	user->printHello();

	delete user;
	return 0;
}