A single-move chain of 6 or more Tile-Chomps earns you a TileBoost -- the most powerful tool in the game. Here's a simple straight down example of Tiles stacked in a Chomping-Chain that can earn you a TileBoost:
2 on 4 on 8 on 16 on 32 on 64
[ In another game this might look like: 1 on 2 on 3 on 4 on 5 on 6; or even 6 on 5 on 4 on 3 on 2 on 1 ]
Placing another "2" on the top of this stack triggers six downward Tile-Chomps, as the placing tile Chomps each tile, stepping up in value with each Chomp. When a Placing-Tile sets off a 6-Chomp (or longer) chain, you earn a TileBoost. Note that the number of Chomps required can vary among games and versions.