There are two private companies advertising on my blog. One started advertising a month before the second one. It’s been six months now. On the first and second month, me and the advertisers use to chat via email (separate conversations, they don’t know each other). They used to tell me how their business is doing, and thank my site. They used to tell me they are receiving leads, but wouldn’t reveal the number of course. We use to advise each other about how we can maybe place ads for maximum exposure and all that.
But now all of a sudden, we do not chat anymore. I just send an invoice at the beginning of every month, they pay and that’s it! The following month, it’s will be a repeat of sending an invoice and getting paid.
I know I did not do anything wrong, otherwise they would stop advertising on my site.
My question: How do I keep a good relationship with them? What kind of questions should I ask them just to start up conversation? Or should I leave things as they are? I’m just afraid if we don’t have some sort of relationship, it will be easy for them to stop advertising on my blog, and I don’t want that because they pay me good money, a lot compared to Google Adsense. :)