I used the numbers for Telegram and WhatsApp, as well as for various online stores. I was only able to register with Telegram on the second try, and with WhatsApp on the fourth. The previous numbers didn't work, and I had to request replacements. This didn’t particularly surprise me, as it’s quite a common issue for popular services. In comparison, I was able to register at all online stores on the first try. If you plan to do mass registrations, it's better to have a reserve of numbers to reduce the time spent on replacements. Also, with large orders, you can save a bit by using the turbo boost for VIP status. For example, when topping up by 1,000 and above, they offer a discount of 5% – it would be foolish not to take advantage of this from the first order.