Without much else going on here in the Midwest, Lebron's shoes will skyrocket in sales now that he is going back to Cleveland. Cleveland loved Lebron. He was an icon to the people, and they are thrilled to have him back. They will reward him with their dollars by buying lots of shoes.
Cleveland is where Lebron started so most of his fans are still there. A lot of his fans were not too happy with him when he left so they may be forgiving and start buying his shoes. I believe he will also play better in Cleveland which will boost his popularity resulting a boost in shoe sales.
The fact that Lebron James has return to play in Cleveland is not going to affect sale of his shoes, which are already very popular. However is will generate a major increase in the sales of Cleveland jersey. When he bolted town the first time a large percentage of them were burned by their owners in protest of his decison to leave.
Lebron's shoes will not be more popular. This is because everyone is familiar with him already and do not see him as anyone who is exceptionally marketable. The biggest athlete with shoes was Michael Jordan, and no one will be able to replicate that success or those sales again. It was a new concept then that took hold.