<human>: Can you provide a brief rundown of the text in within 3 sentences?

I previously had money invested with Betterment, but I eventually pulled out and put it in Vanguard because Betterment wasn't giving me anything Vanguard couldn't. 

Now Betterment is trying to lure me back with their promotion of free TLH for any user regardless of account balance. They claim they can increase your returns by over 3/4s of a percent, which if true, sounds great. Of course, I realize this is 'up to', and could mean anything between and including 0% - .77%.

I also realize I can do this as well, selling securities at a loss and buying similar ones. But add this on to the rebalancing and nice interface that Betterment has and it's starting to be worth the .25% they would charge me. I'm not going to take my money out of Vanguard, but I am considering just putting in $100/mo into Betterment to see how it fares against Vanguard despite the .35% fee bracket it'll put me in.
<bot>: Is TLH just some fancy, optimistic idea they're throwing around, or is .77% unrealized returns a real thing?