Branding is the process of unleashing the potential of your product or service by creatively developing and successfully delivering a unique, consistent and memorable "identity" for it.
Success metrics are subjective but can include:-
- Top of mind prompted and unprompted brand recognition and awareness (through field studies/ market research)
- ROI (has the branding strategy had a measurably favorable effect on sales)
- Customer feedback (would customers buy the product? would they recommend it to others? what characteristics do they associate with the product?)
- Employee rapport (do your own teams and employees and investors and stakeholders feel pride and affinity to the brand?)
Time-lines for assessing KPIs will depend on the KPI and the nature and ambition of your banding campaigns and activities. Great viral campaigns will by definition snowball and reap results in terms of generating awareness faster than very focused activities specially targeted at a niche group that remain niche; but the nature and scope of campaigns will differ based on your objectives and also industry to industry and target market to target market etc.
Branding is a process and in fact a quite delicate one, just like giving birth to a baby and raising him/her. Like a new born baby, a new born brand is just as fragile and has to be handled with extreme care, any roughness in the beginning could create unimaginable harm and hence things should be planned out very well before the brand is actually born and is under scrutiny by the public.
In regards to the KPIs, there are three critical ones and perhaps over 20 other important ones, I would argue however the three most critical KPIs are: Awareness, Attitudes and Usage.
As far as judgments, I think it depends on the targets you have defined for your brand, for example if you have created a brand to compete with Coca-Cola (not that I suggest you do) it might take a decade before you can start to judge.