Voting as a nice way of letting the writer know you enjoyed their work.
As a writer, votes are valuable feedback as a visual representation of audience enjoyment. They give your book more readability so others are more likely to check it out, creating a snow-ball effect.
Votes can also be a misleading representation of your work because reads can forget to vote, or even not have a Wattpad account, so can only read your work.
You can encourage voting at the end of a chapter, however this can disrupt the flow of your narrative, or come across the wrong way.
There is always going to be a gap between the amount of reads and votes.
It's unavoidable and not something to get concerned about.
(More in the reads to votes ratio chapter)
Votes come gradually as more members stumble across your work.
Voting is also incredibly important as a part of engaging with the Wattpad community.
Voting sends a notification to the writer, essentially with a link to your profile.
Supporting other members and making friends here through voting is bound to bring you some votes and support back.