Here's an interesting SEO problem you can solve at Your SEO Plan. The site offers you multiple-choice questions that guide you step by step in solving the mistery.
"Your friend mentions to you that she’s disappointed with her website’s performance in the search engines. The site isn’t ranking well and she doesn’t know why. It’s a comment you hear a lot, but you’re surprised to hear it from her. Her restaurant, Providence, is one of the hottest places to dine in Los Angeles.
Of course, your friend is a restaurant owner, not a web marketer, but still... with great press and a huge clientele, shouldn't the website be doing well without much of an effort from the restaurant management? You decide to investigate, using your SEO skills."
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