SQL server and MySql replication

Just had a chat with are web developers. They say they can set it up so are local sql server with automatically replicate with their remote web server.
I know you can do things with linked server in SQL server but I can't see how this isn't going to have a severe negative impact on the performance of are local server.
If anyone has any opinions or better still any good articles on this that would be great.
The closet I've found is the below
SQL server and Access
As far as I can see though the SQL server is having to do twice the work.
Once again any opinions would be very welcome.

SQL Server (compared to Access at least) is very good at dealing with multiple things to do at the same time. As it is server based (rather than client based like Access is) it has a huge amount of extra processing power, in terms of CPU/Networking/etc.

If you are in doubt, check out Task Manager on your server, and see how much CPU utilisation there is, and how much of that is SQL Server processes - it will presumably be quite low (10-20%?), in which case the difference from replication will probably not be noticable.