How best can one sustain an online presence using domains?
You must have a kenyan domain, a .KE domain. To create a serious online presence, move away from the social free aspect that you have and get a domain name that speaks about you. Ensure that you have a reliable online presence, by creating your own. A domain name will give you credibility.
People want to know who you are, they want to be able to trust you. A domain name is you speaking about you and what you do. They are checking if what you are saying is trustworthy and a domain name creates an infrastructure for you to maintain that trustworthiness and making sure people understand who you are, and what you do. The best part is, you have control of the information.