You do relise that the owners of these cloud based crm systems have access to all your customers data, your business, and potentially can ruin your business with one mistake?
Coming from an IT background; don't beleive the garbage that 'they cant access your data"....trust me they can..and will if pushed to do so by greed; criminal intentions; or government requirements
Anyone who understands data programming can potentially use your data against you.
i would never trust my companies customer base on a third party data centre or crm system. Its just ludicrous.
Keep your data yours...dont share it with anyone else.