Yes if you're trying to measure and compare visitors to the shop. Furthermore, if visit to chocolatiers everywhere are down, and then one opens up free samples and reports the highest number of visitors ever, that doesn't indicate increasing interest in chocolate either. For all we know, 90% of those visiting the chocolate tried chocolate, hated it, and will never buy any. Footfall is no use. In the case of GP, the price of entry is the shopping mall. Just because there's a chocolatier there handing out free samples that lots are trying, doesn't mean those people are interested in chocolate.
Any product changing to a free model is not going to be generating data comparable with previous data, and can't be used as such. Once established as a free model, future comparisons between products in the same sales model will be comparable and useful, but between GP titles and non-GP titles, it's useful numbers.
My view may be wrong. I'm chiefly basing it on activity some years back where a number of driving game studios closed/were absorbed and someone, possibly Codemasters, said car games just weren't selling. Maybe things have turned around since then? But size of a free sample driving game userbase is not indicative of growth or even a healthy market for paid-for driving titles. That evidence will have to come from elsewhere.
there aren't free samples , the people are paying to access the samples.
I think you need a new example than this.