The myth that you need a long performance history to get a better score is not true.
With Google your performance history is established in two to three weeks. Google does like accounts that are around longer, but that will not severe your score completely. If you follow the other suggestions we have made in dispelling myths you will find that there is not a disadvantage for shorter term accounts.
Related posts:
- Myths: What You Should Know About AdWords – Part 1
- Myths: What You Should Know About AdWords – Part 8
- Myths: What You Should Know About AdWords – Part 7
- Myths: What You Should Know About AdWords – Part 4
- Myths: What You Should Know About AdWords – Part 5
- Myths: What You Should Know About AdWords – Part 3

