The market is currently dominated by J2 Global. Their main website is eFax.com but they also have several other web properties including fax.com, rapid fax, send2fax, jblast and a few others.
As the brand leader in this field, they have good support but the highest service fees and most restrictive end user policies in the industry.
For example, they are the only company that will NOT allow you to transfer your fax number (port fax number) to a new carrier. Remember when the cell phone carriers used to do that...it took an actual 'act of congress' to open up the market. That has not happened with fax numbers.
Well, eFax has a good reason to try to hold on to their existing customers. Market pricing has dropped to half of their current rates - and most new customers choose a different carrier. Today, a common price point is under $10- a month for up to 500 pages. In fact, there are even some free (limited) services available. So, if they allowed their customers to move their numbers to a lower cost carrier, they would probably loose a good portion of their business.
Ask any competitive efax service provider and they will tell you that they frequently get letters from the lawyers at J2 Global. Mostly, they threaten to sue the small operations for even the grayest of trademark infringements, like mentioning on their website that they are cheaper than eFax. They play hardball.
However, since the technology behind fax servers is very mature, even the smallest providers are using state of the art equipment. Basically, the same service for half the price.
