Adwords is a channel with a lot of potential and highly targeted traffic for every business that is not hugely innovative.
The cost for some keywords can be extremely high and it will keep going higher and higher, because that's the nature of paid advertising. If we take this into account, you want to start as early as possible and make it profitable, so your account has both historical data and a healthy track record. This guide includes tips to reduce Adwords' cost per acquisition in the Adwords level (not landing page optimization etc).
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