I got my degree in International Marketing and Japanese in Dublin and I worked there for just over two years before moving abroad. I know lot of people with marketing degrees in Dublin and there are less marketing jobs than canidates from my experience. Then again you are specialised in online marketing which should make you much more attractive to employers and you can speak another language which is also an advantage. I think you wont walk into your perfect job straight away so you may need to take any job quickly to get by and then be on the lookout for something more suitable. My Spanish friends had to do that when they first moved to Dublin. The main thing is dont be afraid to come to Ireland, come over, get a job doing anything, a junior marketing position or even if it is working in a bar/cafe/restaurant and then look for better job.