You should also be wary if

• that website you're about to spend thousands on, doesn't have a physical address.
• the album has the suffix "Part 2".
• they claim to be "The Drifters".
• the term "fun pub" is used.
• the sign says "students welcome."
• they can't be fed after midnight.
• you can't get them wet. Ever.
• the only reading material is bound in human skin and has the word "Dead" in the title.
• the celebrity endorsement is by Sue Pollard.
• you get a free laptop / games console just for signing up.
• you just have to pay the tax on your flights.
• they don't have any, but they can order one in for you
• they don't have any, but they do have one that's "just as good."
• it says "Amstrad"
• it can be enjoyed as part of a "balanced breakfast."
• it requires you to have a "healthy lifestyle."
• it's full of natural goodness.
• it contains no non-artificial ingredients.
• it's not just any food, it's Marks and Spencer food.
• the letters "q" and "u" have been replaced with "k" and "w."
• words ending in "y" have been changed to end in "ie"
• the supermarket has prefixed it with the word "value".
• you're told the colour of the wiring isn't important.
• you get a vote of confidence from the chairman.
• people around you start spelling words out.
• you're linked with the QPR job.
• there is a TV programme where you can win £100k simply by dialling a telephone number and naming something you'd expect to find in an envelope that begins with the letter "R".
• you are related (no matter how remotely) to Jessica Fletcher.
• there's a flash on the box saying "as seen on TV".
• beside their picture, is the name of their TV character and the TV programme they appear in.
• it's been called a "stunning return to form."
• there's a no obligation, 30 day, free in home trial.
• they've been dead for 20 years yet the latest "greatest hits" album features new tracks.
• it's described as a "re-imagining" 
• a group of kids and their pet dog turn up in a van and start investigating paranormal activity.
• your friends start avoiding daylight and develop a dislike for garlic.
• your neighbour has taken delivery of a food processor and 10 tonnes of fertiliser.
• it says "too raunchy for TV".
• it's cheaper when there are none in stock.
• you win a competition you didn't enter.
• it's a DFS sofa not in the sale.
• your house was built on an ancient Indian burial ground.
• a recruitment agency says they'll definitely ring you back.
• it includes the word "virtually".
• the manufacturer claims it's the next big thing.
• a serpent tells you it's okay to eat the apple.