What made me switch in the past was my host being acquired by another Company, who started to save or "optimize" how they call it, so the service and support got much worse.
With an annual billing period this meant you were locked-in paying for a service that was no longer meeting my requirements.
This is exactly the one single thing that I may hate the most - all these special deals that turn into a long term / auto-renewing commitments / with hidden fees and fine print.
Where you may eventually find that, if you need any, often basic additional features, you'll pay premium. And if you're not satisfied with the service, you can quit, but you're already locked in and you keep paying anyway.
By the way - I made this check-list of questions to ask, when reviewing a host , maybe it can be useful - so I'll re-iterate it:
---
1) do I understand from the specifications what I'm buying ?
Many service specifications are a bit complex and can get tricky with fine print.
2) what's the payment terms - any hidden fees or price shifts ?
What I don't like personally are these special promotions, then once the promo period is over you get charged notably more, including extras that you may deem included as default.
3) is the sales team easy to reach for clarifications?
This of course is a huge plus - if you send a request, you'll need a qualified, and ideally a timely answer.
4) if I'm not satisfied with the service, can I cancel and switch?
Top important - many hosts will lock you into long term contracts, that are hard to get out of if you are not satisfied with the service.
From more of a tech stand point:
5) what's the variety of services offered, will it be easy to upgrade, as my requirements grow?
Say that your traffic grows, you'll need additional services like CDN, or cloud, to upgrade your server - solid host should have that in stock and be eager to deliver for their existing client.
6) do they own their infrastructure?
Very important, it's not that difficult to advertise a hosting service as a reseller, but of course, if you want something more complex, including the right price / value ratio, you need to look into actual hosts that own their infrastructure, so you can go direct (not to pay the middleman).
7) where are the data centers located?
Not only regarding the connectivity, but also due to the legal landscape that may affect various types of online businesses (especially high risk).
8) is there a solid CDN option available?
As your site grows, if you want to do numbers, or even if you're a media buyer that moves volume and wants a super fast and stable loading time with his landers. You may want to search for a solid CDN with straightforward, per usage pricing.
9) And of course, how experienced is the team when it comes to assisting with your needs, or migrating your existing websites from another host.
An experienced team hosting hundreds and thousands of web setups can even advise you, regarding various scripts or setup, to fit the purpose and requirements regarding your particular needs.
