Well, in this case clearing the storage won't be enough as it seems like the ad uses the device identifier to track you and restore the database right after.
The point is pretty moot anyway, since native applications can and are using the device ID to track you, and it is unique.
On my iPhone I have native apps installed for accessing ... Twitter, Facebook, LinkedIn, Google Reader, Yahoo Messenger and Skype. I prefer native apps, even for Facebook which has a kickass web page optimized for mobiles, and I'm sure I'm not the only one.