What are the key concerns you might have while switching from one marketing platform to another?

What do you mean by marketing platform? Do you mean online marketing platforms like those:

http://www.doz.com/analytics/-top-online-marketing-platforms

Dear Sidrah, "marketing platfoms" you mean social media platforms?

If so, well, in my opinion mostly is about public segmentation. Your´s clients/visitors/publics profiles are different in the diverse social media sites. 

In all of them, the purpose is "dialogue" with them and somehow make them talk about your brand. 

In a general way, the profiles can be divided into:

a) Sporadics

b) Likers

c) Sociabilizers

d) Discussants

c) Actives

Understand these each one profiles characteristics, among other segementation analysis, like social, age, demographic, and so on, will be useful to build a specifi strategy/advertising to each social media that we use.

The aim, obtain engajment and make the feel sentimental attached for the brand and the values that it represents.