Imo trainseats is very valuable - it is short, very memorable, and it has a clear association with train tickets but in a more relaxed if you wish "fun" language. Personally, i like trainseats.com more than traintickets.com - the former just "sounds" better! (even though the latter is good too)
With correct development, this could be a winner among the sites for selling train tickets, arranging train journey etc.