No quick, easy integration with Salesforce (at least, not that I've found).
Limited reporting capabilities. Even limited CSV exports. I had to spend an entire day, once, doing vlookups in Excel to get a report I needed. (On the other hand, Wishpond is a very affordable app, so if one looks at the total cost involved in the use of this app, it's still very affordable.)
I found it a bit confusing to remove my Wishpond landing pages from my Facebook page.
We've obtained tens of thousands of dollars in business using Wishpond, and yet spend only a few thousand dollars to do that. It's been an amazing tool for us as we get some traction with our business.
As mentioned before, I did have to spend an entire day, once, creating a report that I needed, as Wishpond didn't offer me the option to export my data in a format I needed. That was really the only negative ROI experience I've had with Wishpond. I still love the product, but I would love to see more flexible exporting options from the tool.
After spending days trying to implement other forms on our WordPress website, to no avail, costing me thousands of dollars, I got beautiful Wishpond forms onto my site within hours (and no frustration). Not only does this save me hundreds of dollars each month, I get thousands of dollars of business from these forms. Nice :)
I find Wishpond to have a better user interface and it offers a lot more options than Constant Contact. However, Constant Contact does have better, more immediate phone support (there is no phone support for Wishpond).