Its not quiet as simple as that, let me explain. As with any industry like accounting, law and surveyors. There will be some providers who are good and some that are not so good. However overall the industry is needed and performs a function or caters to a need.
Firstly you need to find out what kind of signals they provide. Some provide short term signals that are taken from the fifteen minute to the hourly chart. Whilst other provide longer term signals taken off the four hour or daily chart.
They are very different services, with the shorter time frames you will get a lot more signals, however they will not be as strong as the signals that are generated on the four hour charts or daily charts.
There are some good providers and some not so good one, some things to look out for are, If the site had a trust logo and if they offer a money back guarantee. If they do its a no brainer because its’s risk free.
Best of luck on your search.