Why does lots of things in republic Ireland feed off uk?

lots of things in Ireland are the same as England, for instance, nearly all the shops in the main cities in Ireland are all uk companies, like Argos b&q next etc. BskyB (sky) provide digital tv with only 5 Irish channels the other 900 odd stations being English. same newspapers, mobile network providers etc. there's even another 02 music venue in dublin. why doesn't Ireland have a more individual and independent Market?