Do the free trial to see why. You'll get an initial impression that compared to the feature rich apps of Wrike, Asana, Basecamp, Teamwork and many others that Paymo is fairly simple. It is but it has some very-well considered functionality around user permissions, pricing and invoice/report generation. The user interface again looks simple but works great.
For us, what's great about Paymo is:
1. Pricing. Great at $4.95 per user. That's a real per user price. 1 user = $4.95 per month.
2. Additional users (we use many collaborators) can then be switched on/off as required.
3. Good user permissions (switch on/off admin, tasks, projects, invoices, estimates, expenses)
4. The general focus on user performance metrics/utilization (with a good dashboard + individual user metrics by hour, month, project and billed/unbilled time.
5. Fantastic, customisable client reporting and wrap-up invoicing with unlimited free client access to these features*.
*The invoice module ($9.95/month per account - which is great way to charge for this) monitors unbilled time with a one-click invoice generation button. That's a great feature whether you use Paymo to send (and receive payments) or not.
In similar fashion, the client report generation tool is cleverly set-up so you can group time/costs by client, user, projects, task lists, tasks, time, day or billed status as well as include the original budgets by project or tasks. For us that's a massive time-saver and a feature-set that not available or so quick and easy to manage on any other PM system we've tried.
The con's on the present feature list (hence why I've only rated Paymo 4 stars overall):
1. There's no easy to see/use UI control over project/task timescales.
2. Equally, no-billable tasks/reminders don't sit as well in the system.
3. Updates aren't realtime, another great Wrike feature.
4. There's no client/guest access to the project details (which I would have thought Paymo could add easily, by making making the default user status 'view only'.
5. Generally speaking Paymo isn't a slick or richly featured as other leading-class PMs.
However, as of May 4th 2016 there's a promise on Paymo's pricing page that Gantt charts, task scheduling and progress tracking is 'coming soon'. Would be great to know roughly what that means Paymo but those three features even if relatively simple but robust (in Paymo's style) would considerably round-off and build-out the Paymo App experience.
Ease of use