The Elite Technique allows players to merge gems that wouldn't otherwise be possible. Without power-ups or any kind of boosts, Kirbbard was able to score within the 800K range (the highest recognized score bracket is 500K). That's because merging gems lets you create Power Gems (these explode) and Hypercubes (these destroy all gems of the same color on the grid at your discretion).
While there's no guarantee that you'll score higher than the Blitz Bot, the Elite Technique is a valuable tactic in player strategy. It's also perfectly legit, so you're not cheating. On top of that, it takes a bit of skill to master as you're still relying on your own eyes and speed to spot the best clusters to use this technique on.
Here's a video with great examples of Elite Technique in action. For newbies who need to take this slow, here's a video tutorial for beginners that gives you the simple lowdown, how-to in both English and Chinese. Once you're done with the basics, move on to the advanced tutorial here.