What happen to google adwords?

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Early about April, I started using google adword. Then, I can easily get visitors without having high click cost. Now as I look at the minimum cost for each keyword to get then active would be $15. Is this happening to everyone using adword where competition of advertising is getting higher or is it happening to me only? I ended using free classified to get a bit of traffic. Share your experience with adword if you are still using.