We haven't started our article writing services on here yet, but I give you some tips to help till we do :>
* Buy 1 article and look at quality.
* Don't go for the cheapest option - you always get what you pay for.
* If they have a team of writers it is harder to see quality as each writer is different, but once you buy a few times you can tell.
* Depending on the quality you need, look for common mistakes like missing out "the", and other grammar.
* See how much editing you need to do after. A good writer will get you the article and it is ready to use, whereas not so good places will require you to edit more.
* Be careful of writers who deliver you articles in word format. This can result in adding it into other software or sites and end up with the headers that word adds, different characters, etc.
Hope these tips help you siegajala.