Is it worth to periodically switch providers to lower the costs of home Internet?

I moved to a new house a while ago and chose KPN as a home internet provider. I enjoyed paying lower fees (€35/mo) for the first six months, and now I'm paying €42.5/mo. There is an attractive offer from Odido with only €20/mo for the first 12 months, but then it's going to raise up to €50/mo at least.

So, I wonder, is it reasonable to use such promotions like this one and periodically change internet providers or there are some other factors rather than money (e.g., some switching complications) that make this idea not viable?