Typically they work very well for a few months and then start to require buy bulk sms service more and more time dedicated to maintenance, which can lead to higher costs in the medium term than a solution supported by a serious provider.
In addition to the commercial scheme, when hiring a company that offers the bot service, it is necessary to consider some very important aspects:

Ease of use . When considering incorporating a bot into communication platforms, the intuitiveness of the tool must be evaluated. This will allow the contracting company to manage the platform easily, without making mistakes.
Support . A bot's operation is constant, and so should the company's technical support that provides the service. For this reason, it is essential to choose a provider with 24/7/365 technical assistance.