I'm sure this is going to go cold but I really wanted a asus t100 and wanted to get the best price possible and this works.
Reserve the tablet online and use TBC (not sure if TBC will work but worth a try)
Then give your o2 priority code. Currently the asus t100 is 289.99. o2 offer is £25off when you spend £250.
They will knock £25 off and its done. Asus T100 for £264.99.
Also picked up a free water bottle from WHSmith on my way back to work with o2 priority ;)
Hope this helps someone :)