I understand the idea the French people might be attracted through the company of pastors, through "revelation" and knowledge that they are in a sense being deceived by the Catholic church through idols and lies from the clergy, but was there much else? I understand coastal towns like la Rochelle would attract individuals to the reformed church as trading was vastly improved under Calvinism as people could trade with foreign, non Christians as well as the ability to work when Catholics could not i.e. festivals etc. etc. Similarly less strains financially from the Catholic church. Any added info would be much appreciated.
Calvinism - and reformist denominations in general - were focused on text. The reinterpretation and rereading of the bible WAS the reformation. Hence, in the beginning at least, those with access to books (urban dwellers) and the literate (again urban workers) were drawn to it.
Also, proximity to geneva was important. As a centre of Calvinist thought, those close to travelling distance to it were more likely to be exposed to reformist ideals.
Thirdly, your point about industries is important, but equally important is the fact that the reason why some converted varied through the country. Amiens, for example, was a textile manufacturing town which was Calvinist for the reasons you mentioned above. Dijon and the surrounding countryside, on the other hand, were dependent on the wine trade. Who was the biggest single purchaser of wine? The Catholic Church; hence Dijon didn't convert.
Fourthly, proximity to evangelist thought in general. Navarre converted as it's queen jeanne d'albret was fond of it. This was why the champion of the Calvinist cause, Henri of Navarre was Calvinist. The nobles were most exposed to it; many princes of the blood were Calvinists. They were more exposed to it than common people as they were on the whole more literate and would have been able to look after themselves of they took the decision to convert. Hence, 50% of nobles but only 10% of Frenchmen converted.
Finally, it was often done in places where total power was less overbearing. Take the Midi and languedoc for example; they were pays d'etats, who had more independently minded local elites, when they converted, it was more likely that their people would follow. It was also to an extent a form of rebellion against the king. Hercule, the brother of Henri iii, converted just to be a thorn in Henris side.