The Giuoco Piano: Jerome gambit is extremely rare and occurs in less than 1 in 10,000 games. From the data, you can expect that White will only have a 39.13% chance of winning, while Black should have a very high 60.87% chance of winning. Since most players have probably never seen this opening and because White has such a low expected chance of winning, it may be well worth it to keep this variation in your back pocket. If you are Black you should have a significant edge and will probably catch your opponent off guard.