I believe it is important to make sure the technology you use is relevant to the content in which you are teaching. If students can see how the technology relates to the content it is easier for them to navigate and understand. It is also helpful if you follow the NETS-S when deciding on what technology you want to use to teach your content.
In addition to Alicia’s comments, I would add that being aware of and using a variety of technologies is important also. What helps one student may cause another student difficulties in understanding.