Are tests for steroids and other related drugs effective?

Recently Alan Abramson published an article where he noticed whether tests conducted by the World Anti-Doping Agency (WADA) were efficient.
The WADA conducts more and more tests for steroids and other related drugs every year. It seems that those that apply steroids and/or other related drugs are caught. One may think that the world of sports and bodybuilding will be soon cleansed from intake of banned drugs. For example, many tests for prohibited medicines have been conducted at the 2012 Summer Olympics.
But several questions appear here. Are these tests sophisticated enough to detect any person who dopes? Are these tests effective?
Let meditate over results of some tests. In 2010 the WADA published statistics according which 258,267 samples were analyzed by 35 WADA-accredited labs. Out of these samples 4,820 results represented atypical findings. Circa 60 % of positives indicated about usage of steroids. Numerous positives were for cannibinoids. 10 % positives were for marijuana. As you see, only 60% out of those who administered banned medications applied steroids. Is it real? Don’t manifest the results of the tests that the WADA doesn’t do the job properly?
Dick Pound, the former president of the WADA, believes that at least 10 % of sportspersons who competed at the 2012 Olympic Games used steroids. He notes that those steroid users that are not clever are caught by anti-doping agencies. He also notices that an athlete who has been caught using banned drugs will fail an IQ test. He concludes that only unwise athletes don’t avoid detection.
So, when you hear that the WADA has conducted many tests to make sports clean, think whether these statements are true. Has the WADA ability to make competitions fair? Why does the WADA note about number of tests?
It seems that the WADA only desires to convince people that the job is done suitably. The WADA tries to secure future funds. This is the reality.