brianleejackson on "[Plugin: Optin Forms] Javascript Error"

Getting the following javascript error reporting... Doesn't seem to be breaking anything, but thought I would let you know.

Thanks!

TypeError: $ is not a function
$("[placeholder]").stickyPlaceholders();

/wp-content/plugins/optin-forms/js/placeholder.js?ver=3.9.1

https://wordpress.org/plugins/optin-forms/