Acceptibility  TAB 
As Bluetooth and Cell Broadcast recieving capibilities can be turned off on users devices it can be argued that if users have these systems on they are requesting localised information including proximity marketing. TAB 
TAB 
Some go further claiming that there is triple opt in with bluetooth systems: TAB 
Firstly the consumer must stand in an appriopriate 'zone'; TAB 
Secondly they must make their Bluetooth handset visible to other devices; TAB 
Thirdly they must accept the transmission. TAB 

In the event a consumer accidentally opts-in they simply click 'no' to deny the transmission and those sending the messages opts them out of the campaign.

Removed from the article as NPOV, could go back in if it was rephrased to be balanced with any evidence that people find it spammy - if there's proof people don't find it spammy - we'd need to link to some original research I suppose?