If you guys recall, this is the guy who wants to come to the USA and make movies based on his ideas. He doesn't speak English and uses machine translation to post and read replies ("what?").
First of all, "How I Met Your Mother" is a TV show and not a movie. TV shows don't typically have trailers because people already know about the show. Trailers are for feature-length movies that need to be promoted before release for viewers to even know it exists. TV shows get commercials (just like any other product), promos, and previews. A preview keeps viewers interested in the next episode. A commercial often promotes the series as a whole before or after it premiers. A promo can be either.
Next, you should limit your search terms to the relevant terms. A misspelled word you didn't even need will only eliminate the results you want. "How Met Mother" yields better results than either "How I Met Your Mother episeode" or "How I Met Your Mother episode" because all the extra words do is limit the search results and the misspellings further limit your results. With a misspelled word, you are only going to find misspelled results! If you aren't sure of the spelling and have enough other words to search, just leave the word out of the search terms. Using "Meet" instead of "Met" creates a similar problem.
Good luck!