How do enhancers induce transcription?
The activators are proteins that bind to specific DNA sequences in the enhancer region. These activators also bind to the RNA polymerase and other associated members of the transcription complex, which makes it more likely for an RNA polymerase to hang around the promoter sequence of the region it enhances.

This in turn increases the chance of the gene being transcribed.

It's basically a little magnet that sucks in the RNA polymerase and then nudges it towards the promoter.