ProntoPro and similar lead marketplaces work like this: you sign up, you receive requests from potential clients in your area and field, and you pay to contact them. For a professional starting from zero who wants a few contacts right away, it can make sense. But it's worth understanding what you're really buying before you build your business on top of it.
The first limit is exclusivity. On this kind of marketplace the same request typically goes to several professionals at once. Whoever answers first or quotes lowest wins. You're not buying a client: you're buying the right to compete in a race, alongside your rivals, over the same contact.
The second limit is that you pay for the contact, not the result. Whether that contact becomes a client depends on how fast and competitive you are, not on something you control. Conversion rates on shared, often cold names tend to be low, and that has to go into the math when you work out what a client acquired this way really costs you.
The third limit is dependence. When you stop paying, the flow stops dead. You're not building anything of your own: none of today's sign-ups work for you tomorrow. It's rent, not ownership. It's fine as a stopgap, but fragile as a long-term strategy.
The alternative isn't 'don't use ProntoPro'. It's don't depend on it. While the marketplace brings you a few contacts, build a system of your own: a page that converts, a low-barrier entry offer like a quiz or a guide, automated follow-up and measurement. In 60 to 90 days it starts producing contacts that are only yours, and the marketplace becomes optional.
The numbers on what your own engine can produce, from my accounts: an ebook funnel in the legal niche brought 1,017 contacts at €1.30 each, exclusive. RicorsoCartelle.it: 1,987 qualified registrations on €1,322 of spend and 136 calls, without buying a single shared name. Costs comparable to a marketplace, but the contacts are yours alone and improve over time.
If you want to know which part of your engine to build first so you can stop depending on marketplaces, the free 2-minute audit on this site tells you in five questions.