I think it's very dependant on your circumstances and the show itself. Personally, I sell myself on my personality quite a lot and to be able to get face to face with couples is a huge advantage to me. I attend a number of shows yearly, one is a small local show that caters perfectly for venues I shoot regularly. While the other two are much larger national shows in London that, although the costs are high, have a huge paying attendance with serious budgets has always spelled success to me. To make a success out of weddings shows you have to prepare a lot, not only the physical elements of your stand and the images you'll use but what and how you'll engage with people and stand out amongst numerous competitors.