Please enlighten me then as to what Cameron was seeking, as you are clearly party to info that the rest of us rely on the media to supply. All I know he returned with was some kind of ‘brake’ on immigration.
1. He wanted to secure an opt-out of any further political integration with the EU, and he secured this.
2. He wanted access to in-work benefits for EU migrants to be prohibited until they lived in the UK for four years. Once again, he secured this.
3. He wanted to prevent migrants living and working in the UK to secure child benefits for children living elsewhere in the EU. He did not secure this, but the child benefit was indexed to wherever the child lived.
4. He wanted greater acceptance that there are various currencies operating within the EU, and that non-Eurozone countries should not have to contribute to Eurozone bailouts. He secured this.
5. He wanted special treatment for the City, which he did not secure as the EU exists to provide a level playing field with regulations applied evenly.
6. He wanted to reduce regulation across the EU to enhance competitiveness, and he actually secured commitments that went beyond what he asked for.
So you were pretty much wrong, both in believing he came back with nothing, and also that he actually went there to half immigration numbers (which, incidentally, is an option already available to EU nations when new members join, but Britain, unlike Germany and France, didn't apply it with the A8 nations).