Hi Dynamoo, what you suspect is correct, if a bot comes in and spiders the entire site then yes you will get lots of hits and low conversions, and also remember as your sub-domain is able to be spidered you will also get a lot of untargeted traffic, unlike any other mobile retailers, therefor you can prob say as a rule of thumb 50% of your traffic is "free"
SEO traffic and not highly targeted traffic that you would normally sent to a phone shop
Any questions then give me a bell on 01427-892976
Steve