Coattailing is an novel use of positioning: "if you liked (blank), you'll also like (blank-plus)". Attributes of the original transfer to the new item, without the expense of market research by the coattailer.
The Long Tail:
"Nick Carr notes an emergent Long Tail strategy of coattailing. Obscure bands, for instance, get free marketing by recording cover version of famous songs, which show up in iTunes searchs for the hit. 'This sort of practice - let's call it 'head-faking' (or maybe 'head-phaking' would be hipper) - has broad applications as a sales strategy for long-tail markets. You simply give your product (whether it's a song, a book, a DVD, a software program, or whatever) some tie-in to a hit product. You might, say, incorporate the hit's title into your own product's title. Through the magic of search technology, your product then becomes a barnacle that the hit carries along with it as it cruises through the limelight.'"