ThisIsOli - 9:58 pm on Jan 23, 2012 (gmt 0)
Snippet bait is not a real term, I use it occasionally to talk about how I use a few words (ie. a twitter post) to draw people in to reading an article and backlinking.
Link bait is any article that engages people and makes them want to provide a link back.
You can do this directly (Ie. mention a related site in good light) or indirectly (ie. create an article on a controversial topic).
There are various other techniques, and it often comes down to personal writing style over particular niches, since some people are better writers in certain areas.