You need to test your data restore. Can you put a blank drive in your pc, install an os and get your data back out of that online database in a timely fashion. You need your data to be flexible and restoreable. I've been burned before by online services, msn/hotmail for example many years ago when it was still useful lost a bunch of my mail. The "you need to use online service xyz" crowd tends to derail a thread as fast as the buy a mac crowd and don't want to listen to anyone who has tried and found they don't work.
My backup drive is an exact copy of my drive in my netbook with the exception of .ios's and my virtual machine images all of which are legal downloads and are not critical. Then I have a pair of backup drives in the safe that I alternate, so three drives would need to fail before I suffer data loss. Plus my restore time is fast. I've partitioned the drive in my netbook so /home is on its own partition and then the backup drives are setup the same way. So I can install the OS on a blank drive in less that 30 minutes and then either just mount /home from one of the backups and use it or copy it back over or at worst case boot from a live distro and mount my data partition and access my files. So that capability is better and faster than most online services and the few that will actually allow you to access files like that the performance is too slow to do a restore in any useful time. Don't even get me started on the idea of using e-mail as a backup, how are you going to attach and e-mail 29,000 pictures and keep track of that many e-mails to ensure you don't miss one if you try to save your attachments as a restore procedure, and yes there are web sites that promote the e-mail as a backup method, its just not scalable.
For all the most important things, the actual documents and not pictures, movies, mp3's I burn cd's or dvd's and put those in my binder as well as offsite. I have a folder on my drive for each person individually then one for the combined important files.
So now I not only have at least 5 copies of the most important files they are actually restorable. One of those dc/dvd copies if 250 miles away. And one more on my wife's computer too.
Then my old laptop is capable of mounting any of those backup drives and reading the files.
All of this requires no internet connection so in a Hurricane Katrina situation where people had to evac their city and needed to give medical records to new doctors and schools or a new resume I have mine available, I don't have to try to find a super fast internet connection to try and sort through and restore from.
Again I say try it, buy yourself a blank drive and have a DR test. I see people test their preps either through a hiking/camping trip or shutting off all the utilities, but how many have tried a test of your computer preps.
Imagine you had to leave your home and were in a hotel, try to retrieve from those inline backups through that hotels 1Mbit connection shared by 300 guests. Those online backup services are successful because 99% of their customers have never tried to restore. Don't take it personally a large percent of businesses don't either, a large statistic of small business go out of business after something even as minor as one of their main office pc's having a hard drive crash. I work in IT and IT security and DR so I see it all the time. Those services are fine if all you care about is backing up and not restoring. But you can't rely on that infrastructure to be available in any type of disaster, if it weren't for the failings of doing a full restore I'd consider them but its pointless to pay for a backup service that you can't restore from.