I think both of them are saying that all viewers should purchase their respective products.
Best brand: It means it has the most attractive qualities and no other competitor in the market is like it.
No.1 brand: It refers to top ranking among all competitors based in certain criteria.
K Mohan @ Moga
'Idhuvum Kadandhu Pogum "
Even this challenging situation would ease
Let us imagine that there are four sections of the same class in a school. Each section will have a No:1 student in that section. Then there will be four no :1s in that class in that school. The person who got highest mark among the four will be the best student and number one of that. Class in that school.
One product may be the best and works well. But it may not be very popular and much sales are not there. Then the product which is having highest sales can be taken as number one.
Knowledge is power.
Thoughts exchanged is knowledge gained.