Why should I use a Delkim Bait alarm?

You shouldn’t.

Personally, I think it’s rather silly. It doesn’t really offer much over the old-fashioned way of fishing, and in fact takes some of the fun out of it, while also costing about as much as a trolling motor. Hell, I could get a custom made carbon fiber pole for less. Just use a 79 cent bobber and put the $100–200 you save towards beer.

That is my opinion, and those who think it’s worth a couple hundred dollars to automate the fishing process instead of actually fishing themselves will think otherwise, but they are free to post their dissent.

Here is another version of a bite alarm. Bitebuzzer
I would not spend the money.