before you could block 4od adverts by using this method

1.Watch the first set adverts from the show of your choice
Pause show
Locate your hosts file (you will need to have administrator rights and change it from read-only)
Windows - C:\windows\system32\drivers\etc\
Mac - /private/etc/hosts
Add these 3 entries on new lines at the end of the file
127.0.0.1 s0.2mdn.net
127.0.0.1 realmedia.channel4.com
127.0.0.1 webstat.channel4.com
Ensure browser is set to not clear browsing history on exit
Link to Chrome options where "Clear Cookies and other site data" should not be ticked - chrome://settings/content
Firefox - Options -> Privacy -> History -> Firefox will Remember History
Close Browser and restart
Watch shows advert free!

however this does not work anymore if someone could figure out how to block lovefilm adverts it would