Good reasons to register
Keep the thieves away
The theft protection decal that you will get from Solid Insurance is meant to intimidate the thieves since the bicycle is registred and can thereby be tracked back to the owner.
Easier to get your bike back
Police department, lost-and-found, customs and insurance companies have access to Solid Register and if these members find a bike they are able to contact the correct owner.
Prevent theft and fencing stolen bicycle
The purpose of a register like Solid Register is to prevent theft and fencing stolen bicycle.