I like that it works across all browsers (desktop, mobile) with no extra work required by myself or my clients as there is nothing for them! No idea how they are making money but you can't get any more secure than this in terms of security - great if your site uses WPML so multilingual features aren’t an issue either.- sometimes pushup doesn;'s popups don"T always appear when expected which could be annoying depending what time/day etc., however we have yet had issues where users were confused why something wasn't working properly after using PUP's service,- not much at present other then minor niggles really? We've been testing various things out since launch including Airtable dashboards linked into our wordpress sites via wpml &.