I am wearing my paranoid tin foil hat, so I am going to be contrarian.
Whatever you do, tell your friend not to change his hosting. There are many reasons for this.
a. It works
If it works, don't 'fix' it. This board is full of stories by people who have seen rankings fall when they have done things like change their theme, add a plugin, or some other tweak which on the surface seemed minor, but set google dancing.
b. Trivial amount of $$
$100 per year is about $8 per month, which is tiny, if the site is already making money. Take it as the cost of doing business
c. Not all hosts are created equal
- New host could be overloaded server , resulting in slower pages
- New host could be full of dodgy site, resulting in penalizing by Search Engines
- New host could be further removed from clients, resulting in larger ping/page load times
- New host could be running different version of OS/DB/CMS etc that might break existing site
- New host could be on a lemon server that continually needs rebooting
d. If you need to ask ...
If you need to ask, you probably don't know enough to do it properly.
- do you have a rock solid plan to do a *hot* migration with no downtime?
- have you tested site on new server setup?
- have you benchmarked these?
- have you got a rock solid rollback plan if migration does not work?
- have you costed all of this?
I could go on, but the short version is, be prepared for something to break when you migrate. Be prepared to see some rank wobbling. Be prepared to take the risk that your site will get slapped by Google.
If the site is already making money, and is working well, then take the $8 per month (~$100 per annum) as the cost of doing business, and do not risk a perfectly good income stream to save just a few cents daily.
