If you look at their Zing package ,
They are offering 17 FTA entertainment channels which don't have any SUN Group , Jaya Group or STAR Vijay channels (I don't count religious channels) for Rs 99 which is definitely not useful for 99% users.
The next pack is priced at Rs 139 , in which they provide 31 Tamil channels which is good for the users who looks only for regional pack. But the rural people who is their target will be migrate to Zing, is a big question mark as they are getting these channels little for lesser price on Analog. Why should they have to invest in STB and pay little more when they get same channels in Analog.
May be if Govt strictly implement DAS in TN then , the people may think about Zing in TN. Zing can get people who are moving towards DTH , but interested only in regional channel.
Still the other packages Anandham & Kondattam looks costly for the channels it has.
And In South Indian market mostly people will look for dual language , Like Tamil + Malayalam. That is also a big miss in Zing!